Ok I guess I found the cause. You are right about E key being used for other things in blender. Things outside keymap config. The following code in blender/editors/gpencil/gpencil_paint.c, line 3772:

I am not changing tools in the middle of the stroke. Please see the steps, I mentioned to make sure the pen tip is released BEFORE switching to eraser. That means the stroke is done and nothing is pressed. I can understand this is not the default way of doing things, but what you said in your post is not what I mentioned in my post.

Checked in version: 2.81 (sub 16), branch: master, commit date: 2019-11-15 16:32, hash: rBeba4a4bd73ba

In T71517#810119, @Erick Tukuniata (erickblender) wrote:

Point to note: if you select the draw brush with mouse selection, you wouldn't see the problem. If you sculpt many stokes with " xkey activated" draw brush, you have to undo all of them before you see Dyntopo deactivated.

Tested on this version also, which is just released : 2.81 (sub 16), branch: master, commit date: 2019-11-12 13:28, hash: rB125257758007

That also happens if I load the file. I load a file (still in factory settings), pressed X to pick draw brush, made one stroke, ctrl-z for undo. The bug occurred.

In factory mode, I used the default keys. I just tested with :

• open blender
• preferences -> load factory settings
• new file
• delete everything
• add new cube
• go to sculpt mode
• enable dyntopo
• picked some brush other than draw (inflate in this case)
• did some sculpting
• pressed X to pick draw brush
• sculpted just one stroke
• pressed ctrl-z for undo

Also, just noticed and tested for few minutes. If I assign shortcuts by right clicking on the brushes in the tools sidebar and use those shortcuts, this bug will not occur. Its only occurring if I assign shortcuts from keymap in preferences.

In T71517#809829, @Philipp Oeser (lichtwerk) wrote:

Also cannot reproduce.

Does this happen with Factory Defaults as well? (File → Defaults → Load Factory Settings)