I'm sorry for my ignorance, but where do I find the GPU string provided by BOINC?
However I think the RX570 is not a substring of the RX5700, because they are 2 GPUs of different architecture see the following links for more information:

AMD RADEON RX570 https://www.amd.com/en/products/graphics/radeon-rx-570
AMD RADEON RX5700 https://www.amd.com/en/products/graphics/amd-radeon-rx-5700-xt-50th-anniversary

This is a "string" from a software perspective, meaning just a series of raw characters. The characters "RX570" are part of "RX5700", which is what we mean when we say "RX570" is a substring of "RX5700". This has nothing to do with the actual graphics cards.

The string given by the BOINC api is printed at the top of the stderr. The stderr is given with each completed task. For example here is one of your tasks:
https://numberfields.asu.edu/NumberFields/result.php?resultid=107841147
And your GPU string is:
GPU Summary String = [CAL|AMDRadeonRX5700XT50thAnniversary|1|8176MB||200]

Yes, I meant the Microsoft Edge browser, which has in the settings>system>Use hardware acceleration when available "enabled".
When I start it, having that option active, probably requiring help from the GPU, it somehow unlocks it, creates the checkpoint, and completes wu processing.
If I do not use this trick and leave the PC to process the BOINC client all day, as I normally do, without intervening, in the evening I will still find the WU to finish because the percentage of processing will be blocked, while the time, always processing, flows inexorable.
At least the system crashes and then it ends first and the WU will go wrong.
I hope I have cleared up your doubts and explained myself well.
Hello.

This almost sounds like a Windows 10 issue, as if it's blocking computation until hardware acceleration is turned on. I'm not a Windows user anymore, but I found online that hardware acceleration can be disabled in Windows 10. Is there any chance this is disabled and that's what's blocking it until enabled by Edge?

But then again, if the old app used to work with your current Windows configuration, then I'm not sure what's going on.

When you get a chance, could you look at the stderr.txt for a WU that's stuck and paste the output here (before you unstick it). That should give me an idea where in the processing it is before it hangs.