I Have two DELL XPS 15 laptops with 7th generation Core i7 https://www.dell.com/en-us/shop/dell-laptops/xps-15/spd/xps-15-9560-laptop and I have been using Deepin on both of them since Deepin 15.2, then 15.3 and 15.4.

When 15.5 came out and after an upgrade, I noticed that the system could on boot to the login screen and failed to load the desktop or any GUI that comes after login. Since after an upgrade (not-fresh install) the kernel that came with the previous version still resides on the system I tried to boot the laptop (now with Deepin 15.5) with an old kernel (that came with 15.4) using ADVANCED OPTIONS on GRUB menu. Selecting the previous kernel Linux 4.9.0-deepin13-amd64 it works. So the new 15.5 could now run but only with the kernel that came with 15.4.

The same happened when 15.6 and 15.7 were out. The only kernel that works is the same old Linux 4.9.0-deepin13-amd64 that is loaded with Deppin 15.4. This means that the newer kernels that are packed with Deepin currently are failing to run on these laptops.

This means that if I happen to do any fresh install of Deepin OS either 15.5, 15.6 or the current 15.7 that that are packed with a newer kernel other than the one loaded in 15.4, the laptop won't even boot.

If I am to install Deepin 15.7 then it means that first I have to install 15.4 and do an upgrade to 15.7 so that I retain and use the kernel that comes with 15.4. In other words, only Deepin 15.4 works from a fresh install on these machines.

Replicating these installations on other machines ended up with all installations working fine for 15.5, 15.6 and 15.7 that come with the newer kernel.

BONUS: I also observed that while on 15.4 (which works fine), any upgrade of Deepin Desktop Environment (dde) breaks the machine to the same state that does when 15.5, 15.6 and 15.7 are installed.

I posted this as feeback to Deepin team some months ago but it has not been responded to. If anyone has a workaround then please help.