I have the same problem. At first I thought the Adobe cloud connection was unstable. I have 1Gbit connection to my ISP. But local xd-files are also slow. But now i think the latest Windows 10 update might be the issue. I am running the latest update of Windows 10 Pro: 21H1. I am reverting now to an older windows 10, since i have deadline thursday. I'll give a update how the downgrade has worked out.
Yep. In my case it's the latest windows 10 update 21H1 that's causing the problems. First I reinstalled Adobe CC suite entirely, using the cleaner tool. But the problem persisted. Then i reverted back to Windows 10 20H2 and problems are gone.