Brightness function keys not working is a knowing issue, most of us have met that.

About keyboard layout indicator, according to their repo on GitHub, it seems that they disabled it for some reason...https://github.com/linuxdeepin/dde-dock/commit/a84c837ba1299d3c35163d0f1f179e1a9df5d677

Similar for my Samsung ATIV book. The F2/F3 brightness adjustion key cannot trigger the gradual increasing/decreasing of screen brightness; instead they turn the screen one step darker/lighter, and no more. The brightness value in the Control Center does not change when F2/F3 is pressed.

same issues for me (and many at Chinese thread)

the unstrict release contains many serious bugs made 20.2 a disaster doomed our enthusiasm into ashes

they made themselves fix some more terrible bugs which caused freeze when upgrading, but far more remains

i dunno deepin developers get enough energy and kindness to solve all these problem, they seemed working hard on other affairs (maybe UOS) 

the volume and brightness sliders in control center should work instead

what only we can do is to wait for a fix

I tried to update two Deepin computers at my home,

one Huawei MateBook X Pro and one normal PC

both get the same error: "Failed to update"
I think something went wrong....

It would be a nice choice to use uniontech OS

As for me, I'm going to change my OS after the next UniontechOS upgrade

Try another kernel like 5.10.5,my probook 455 is well with 5.11

For me that issues are bugs. The developers must resolve bugs and create one of most beautiful distribution of linux, not create new bugs from old one (deepin 15.11 it has same issue foe keyboard layout language indicator).

I do it that. I try the two different version of kernel with same behavior. I try with iso 20.2 to run like live OS and has the same behavior.

It might be a bug.

This is the same probelm I had on a ASUS laptop and also my PC box. It is very disappointing. However, on my toshiba laptop it installed properly. How do you explain this? The developers didn't test this first. It seems like the copany is using the Community edition to test for the UOS commercial edition - like Fedora for Red Hat - except the Fedora community is stronger and supports the Fedora project.

Deepin Linux is still one of the most user friendly and best working Linux operating systems currently available
It's indeed a shame that the last update didn't work, but still everything is working perfect now on my Huawei Matebook X Pro, I still can do every task I wanted to do, so I will be patient a just wait till they fix the problem

I am even planning to buy a second Huawei D15 (2021 model) laptop and install Deepin on it for my wife, she love's Deepin Linux also :-)

I reinstalled my laptop, and made a clean install of Deepin 20.2
The "Failed to Update" problem is now solved!

So my advise is to first backup your data, and your webbrowser bookmarks, on external USB harddisk.
Then do a clean install, and choose for open source videocard driver (not mark use propieraty graphics driver) and the update problem is solved