Ok... here's the thing. I downloaded and installed the 06.06-release and it gave the same problem and I couldn't log in again. I tried to create a new ID using my iCloud ID on a cellphone and used that to log in, it works. Yes.If I remember correctly, we've used the 2021.06.04-release here in the US in the past. The message still pops up about Google Play services, but you can just hit ok and you are able to log in without issue and everything works. I will pull out a SR25 and test again as it has been a while.
However the Soundcloud ID that I've always used with 6 years of history, followed artists, etc. - nope; I think I'll have to manually add them to the new ID
Not my ideal expectation when I've spent a fair bit on this, but I guess I don't have an option but to make do until a fix is found.