AutoSave files are saved in temp directory, make sure you are looking in the right place.
File > Recover > Auto Save...

https://docs.blender.org/manual/en/dev/troubleshooting/recover.html

Yes, but I don't get any temp, tmp or other folder with autosaves ether. And when I press File > Recover > Auto Save... I don't have any files there.

https://pasteboard.co/JqgFqFG.png

Try running Blender from the Terminal.

cd /Applications/Blender.app/Contents/MacOS
./Blender

Then close Blender. There (in the normal case) should be a report like:

Saved session recovery to '/var/folders/78/83_rsx0j1jb338_yc2gbsyz00000gn/T/quit.blend'

What do you have? Also wait until autosave, there may be an error message.

I get this from ther terminal:

haffy@MBP-Haffy ~ % cd /Applications/Blender\ 2.9.app/Contents/MacOS
haffy@MBP-Haffy MacOS % ./Blender
Read prefs: /Users/haffy/Library/Application Support/Blender/2.90/config/userpref.blend
found bundled python: /Applications/Blender 2.9.app/Contents/Resources/2.90/python
register_class(...):
Warning: 'CloudIssuesList' doesn't contain '_UL_' with prefix & suffix
register_class(...):
Warning: 'NodeReportList' doesn't contain '_UL_' with prefix & suffix
2020-09-09 12:52:50,450 ; INFO ; #### LOGGING START #####
2020-09-09 12:52:50,450 ; INFO ; Blender Version ; (2, 90, 0)
2020-09-09 12:52:50,450 ; INFO ; Bl Build type ; b'Release'
2020-09-09 12:52:50,450 ; INFO ; Bl Build Branch ; b'master'
2020-09-09 12:52:50,450 ; INFO ; Bl Platform ; b'Darwin'
2020-09-09 12:52:50,450 ; INFO ; Bl bundled python ver ; 3.7.7 (default, Jul 8 2020, 14:54:17)
[Clang 11.0.0 (clang-1100.0.33.8)]
2020-09-09 12:52:50,451 ; INFO ; cr build type ; release
2020-09-09 12:52:50,451 ; INFO ; cr build branch ; trunk/Blender_addon/2.80/User/Crowdrender r$LastChangedRevision: 1541 $
2020-09-09 12:52:50,451 ; INFO ; cr logging mode is ; 20
2020-09-09 12:52:50,451 ; INFO ; cr version is ; (0, 2, 8)
2020-09-09 12:52:50,451 ; INFO ; System architecture ; x86_64
2020-09-09 12:52:50,451 ; INFO ; Computer name ; MBP-Haffy.local
2020-09-09 12:52:50,451 ; INFO ; Platform details ; Darwin-19.6.0-x86_64-i386-64bit
2020-09-09 12:52:50,451 ; INFO ; OS version ; ('10.15.6', ('', '', ''), 'x86_64')
Crowd Render user_session add-on enabled
chocofur_model_manager_28 updater verbose is enabled
chocofur_model_manager_28 Updater: Read in json settings from file
chocofur_model_manager updater: Running background check for update
2020-09-09 12:52:50,493 ; INFO ; CRClient Network interfaces initialised
starting crowdrender...
hash_tree created
top hash changed, new value: 8273020388897257154136175873457376
Crowdrender: number of hash tree nodes: 25
Crowdrender: mem usage for hash tree: 3040
STARTED CROWDRENDER
Blender 2.90.0 (hash 0330d1af29c0 built 2020-08-31 12:16:14)
Blender 2.90.0 (hash 0330d1af29c0 built 2020-08-31 12:16:14)
Read prefs: /Users/haffy/Library/Application Support/Blender/2.90/config/userpref.blend
Read prefs: /Users/haffy/Library/Application Support/Blender/2.90/config/userpref.blend
found bundled python: /Applications/Blender 2.9.app/Contents/Resources/2.90/python
found bundled python: /Applications/Blender 2.9.app/Contents/Resources/2.90/python
Crowd Render Client Interface Process ready
Crowd Render Server Interface Process ready
chocofur_model_manager_28 updater verbose is enabled
chocofur_model_manager_28 Updater: Read in json settings from file
chocofur_model_manager updater: Running background check for update
chocofur_model_manager_28 updater verbose is enabled
chocofur_model_manager_28 Updater: Read in json settings from file
chocofur_model_manager updater: Running background check for update
2020-09-09 12:52:54,501 ; INFO ; SIP is AlIVE
2020-09-09 12:52:54,532 ; INFO ; CIP is ALIVE
2020-09-09 12:52:54,532 ; INFO ; sent refresh requests for user credit, node list and

rental instances

Info: Saved "untitled.blend"
Saved session recovery to '/var/folders/0n/9j6c5rxj6wjcct0fwrj9zw840000gn/T/quit.blend'
Traceback (most recent call last):

File "/Users/haffy/Library/Application Support/Blender/2.90/scripts/addons/crowdrender/src/py_3_7/cl_int_start.py", line 65, in <module>
  cs_manager = client_interface.CRClientServerManager()
File "/CR_BUILD_SYSTEM/client_interface.py", line 1217, in __init__
File "/CR_BUILD_SYSTEM/client_interface.py", line 1543, in cs_manager_main
File "/CR_BUILD_SYSTEM/client_interface.py", line 1355, in process_msgs
File "/Users/haffy/Library/Application Support/Blender/2.90/scripts/addons/crowdrender/lib/Darwin/3_7/zmq/sugar/poll.py", line 103, in poll
  return zmq_poll(self.sockets, timeout=timeout)
File "zmq/backend/cython/_poll.pyx", line 143, in zmq.backend.cython._poll.zmq_poll
File "zmq/backend/cython/_poll.pyx", line 123, in zmq.backend.cython._poll.zmq_poll
File "zmq/backend/cython/checkrc.pxd", line 26, in zmq.backend.cython.checkrc._check_rc

zmq.error.ZMQError: Socket operation on non-socket
Error in atexit._run_exitfuncs:
Traceback (most recent call last):

File "/CR_BUILD_SYSTEM/client_interface.py", line 3534, in shutdown
File "/Users/haffy/Library/Application Support/Blender/2.90/scripts/addons/crowdrender/lib/Darwin/3_7/zmq/sugar/socket.py", line 584, in send_string
  return self.send(u.encode(encoding), flags=flags, copy=copy, **kwargs)
File "/Users/haffy/Library/Application Support/Blender/2.90/scripts/addons/crowdrender/lib/Darwin/3_7/zmq/sugar/socket.py", line 416, in send
  return super(Socket, self).send(data, flags=flags, copy=copy, track=track)
File "zmq/backend/cython/socket.pyx", line 728, in zmq.backend.cython.socket.Socket.send
File "zmq/backend/cython/socket.pyx", line 769, in zmq.backend.cython.socket.Socket.send
File "zmq/backend/cython/socket.pyx", line 135, in zmq.backend.cython.socket._check_closed

zmq.error.ZMQError: Socket operation on non-socket

Blender quit

Blender quit
haffy@MBP-Haffy MacOS %
Blender quit
haffy@MBP-Haffy MacOS %

Try also renaming the 2.90 folder or moving it to a different location.
This way you can run a clean Blender without add-ons or settings.

/Users/haffy/Library/Application Support/Blender/2.90/

What happens when you press "File" > "Recover" > "Last Session",
the quit.blend is saved in the same folder as autosave.blend.

Saved session recovery to '/var/folders/0n/9j6c5rxj6wjcct0fwrj9zw840000gn/T/quit.blend'

So it should be here:

I have now downloaded a new 2.9, put it inside a "Blender 2.9 default" folder inside "Applications" and checked that default settings is used, and then I ran it from the terminal. And this is what I get, and I GET AN AUTOSAVE file :) Finally some progress, I thought it was a myth ;)

Read prefs: /Users/haffy/Library/Application Support/Blender/2.90/config/userpref.blend
found bundled python: /Applications/Blender 2.9 default/Blender.app/Contents/Resources/2.90/python
Info: Total files 0 | Changed 0 | Failed 0
Saved session recovery to '/var/folders/0n/9j6c5rxj6wjcct0fwrj9zw840000gn/T/quit.blend'

Blender quit
haffy@MBP-Haffy MacOS %

Yes it is solved.