Yes, obviously, some app screwed up it, or there were some glitches in the iCloud.
Yes, I tried to select all and delete from my Mac, but it is interestingly not syncing the deletion to my phone or pad. I asked for apple support a few times in the past two years, but no updates were heard from them. I tried the new iOS 17 and hopped this is fixed. Sadly, it is still there. I'm planning to register a new Apple ID now, but all my purchase history will be gone. I am still hesitating to move forward on this issue. Every time it gets stuck when I'm typing (it slows down the typing because the system is trying to search all 5000+ items in this text replacement) really drives me crazy.
Thanks for your input and help, though! Really appreciated.