Windows Sync Service is Very confusing and I need help please

[Meowth LVL255]

I can't get my laptop to synch to my desktop theme. Passwords and Edge sync worked just fine, but I noticed a weird phenomenon this afternoon. I turned on my older laptop which synched the theme just fine, but I then noticed that it was asking me to verify my account since I'd reformatted and left it alone after just logging in. For some reason right after I verified, Windows synched to the original W10 theme on the old laptop. I'm very confused, I've been working on this problem for 3 days and I can't get any real answers form MS or Google searching other than "Turn synch on." and "Update Windows." Everything is updated, everything is on, everything is working except theme synch. How do I get this to sync? Is there something I need to do to tell which computer is hosting the theme? I would honestly like to know that information as well. Also, dism and SFC scans didn't do anything as there's nothing actually wrong. There's just some arbitrary setting somewhere in the OS that I or many other people don't know about and I need to know what that is. Any help would be appreciated from anyone.