In my application I have a Navigation menu which uses entries up to level 3.
This worked fine in Apex 20.1, but after upgrade it will no longer show the Level 3 entries.
Is this a known bug?

[Edited 4-Nov-20 after further testing]
As work-around, I added an additional navigation entry
Menu item 1.1 works fine, but item 1.1.1 is NOT showing as expected. Not by hovering over 1.1, not by clicking on 1.1.
Menu items 2.1 and 2.1.2 are working fine again.
So the bug in Apex 20.2 is, that ONLY the first level 2 menu item can not have a level 3 menu.
As work-around I can rework my application to achieve this, but this is something which was working fine in Apex 20.1
