'Bought 2 3 keys off the sites advertised on TPU.
1st, I had an issue with, and in less than 12hours I had a reply w/ detailed instructions, that worked. No new key needed.
WS2019, IIRC.
2nd, was 100% fine.
Win 10 Pro, IIRC.
3rd, I bought, expecting to have a problem. Specifically...