System Information
Operating system: Windows-7-6.1.7601-SP1 64 Bits
Graphics card: GeForce GTX 970/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 436.30

Blender Version
Broken: version: 2.81 (sub 10), branch: master, commit date: 2019-09-10 22:12, hash: rB4ce3fbd52ae8
Worked: 2.79

Short description of error
Hello :) if you spread leaves via hair-particles on a tree .... and then spread that tree on your terrain, again via hair particles - the "sub"-particles (leaves) not get rendered.
true for eevee&cycles - also for final rendering in both engines
in 2.79 viewport the sub-particles have also not shown up in viewport - but in final render they did render
in 2.81 they dont render at all - in both engines

Exact steps for others to reproduce the error
please open the attached blend and hit F12
the original tree show the leaves... the same tree that i spread via particles on terrain do not render the leaves at all - also not with F12
also switch to cycles > F12 > they do not show up in the render & viewport - on both engines

thx for your nice work on 2.8 and have a great day everybody