Operating system: Linux (Debian bullseye)
Graphics card (tested device 1): Nvidia Geforce GTX 1070
Graphics card (tested device 2): Intel UHD Graphics 620
Broken: current master (2.83.10)
Worked: 2.82a (kind of at least)
Short description of error
In 2.82a you could go into x-ray mode and at least see the front side of your
weight paint if there was no object in front. Now it's always just like there was
an object in front, the weight paint isn't shown.
This is a bug that was fixed in the process of T56865 but is now reintroduced.
May be related to T75076.
Exact steps for others to reproduce the error
Paint one corner of the default cube in weight paint mode and toggle x-ray on.