For a long time I used Xubuntu 17.10 and everything in it completely suited me, but with the release of 18.04 I ran into a couple of minor troubles. I now have both of these systems using the common home section and problems only arise at 18.04, so it's not about the local user settings, but about the system itself.
First of all, right after installation, I got to install the video card driver (nvidia). At 17.10 the latest version is 384, I have no problems with it. At 18.04, version 390 and it seems to be working, but after installing ForceCompositionPipeline = On (this option solves problems with the tearing), the system hangs tight when you first start and in order for it to hang, you have to lock the session and unlock it again (with the xflock4 command). And here comes the second oddity.
The lock screen does not have a standard resolution (1920x1080), but some other one. I googled for a long time how to change the resolution when locking and found only articles about changing the resolution of this screen when the system boots, but the fact of the matter is that the bug occurs only in the case of a screen lock!
In general, I decided to fix the hang problem by installing an older driver (340), but the lock screen resolution is still horrible.