WatchGuard Mobile VPN Won't Connect With Correct Username and Password On macOS 10.15.7

I've recently acquired a new iMac. I was running WatchGuard on a MacBook Pro and it was working there. On the new iMac, I was able to connect with WatchGuard on the new iMac for a few days, then one day, it kicked me off and now it will not allow me to reconnect. I keep getting this error: "Logon failed, please check your user name or password," despite my credentials being correct. I can still connect from the MacBook. Both devices are running 10.15.7. I've tried uninstalling and reinstalling WatchGuard, but that has not worked. I did notice that on the MacBook, a folder is created: /Users/my_username/Library/WatchGuard, which has contents in it after installing WatchGuard, but on the iMac, this folder is empty after installing WatchGuard. The permissions on these folders are identical.

I can't seem to figure out why the iMac can no longer connect (even though it was able to) and the MacBook can still connect. Any help is greatly appreciated.