@AngledLuffa and @saygi,
You may want to look in the following thread:
...or most likely in this thread:
I think the latter (Factory Restore Tool) would be interesting for you, but I have a feeling it will not help.
My friend had a similar problem of his Pro1 maybe a year ago (or more) which has started the same way and ended up with a factory replacement device.
Flash tool could reach the device, but it has failed reaching its internal flash storage, most likely UFS flash IC became dead in his case.
(So, it was either a soldering problem or IC fault but the result