Old and long closed iCloud tabs keep showing up on Safari across all devices.

For some time now, I have been having an issue with iCloud tabs in Safari. Regardless of which device I open Safari on, there are always a bunch of tabs listed that aren't open on any devices, and haven't been opened for several months or more in some cases. I have turned off and on Safari iCloud syncing on all devices, but that doesn't seem to work. I have also disabled the syncing, shut down the device(s) all together and then reenabled syncing when they were booted back up. This seems to only partially and temporarily fix the issue, since not long after I reopen Safari I will see several old tabs that will return. Is there anything else I can do to fix this?