Apple Watch 5 is not removed properly from My Find after unpair

I have an Apple Watch 5 that I bought a few years ago as second hand. The previous owner (who is the first owner) properly reset the watch to factory settings and removed it from My Find. I was able to pair the watch with my iPhone and use the watch without any issue until now. I had to bring the watch to an Apple service point now and the claim the watch is still not removed from My Find. I unpaired the watch myself in front of the Apple service guy and the watch is not visible in My Find app nor on iCloud/find web page. I`ve even checked with the previous owner and the watch is not on his My Find either. The funny thing that I can still see the watch in my Apple Support app under My Devices, but of course I can`t do anything there. What can I do now?