After Win10 2004 update can no longer connect to my samba server

I run an openSUSE 15.1 server with samba shares. I've always been able to connect to my shared folders using Windows 10. However, after the Win10 2004 (May 2020) update I now get this:

Error code: 0x80070043 The network name cannot be found.

I can ping the server and even connect to it using another PC w/o the update, so it appears something is now broken. Has anyone else experienced this?

EDIT: My smb.conf file contains win protocol = SMB2. Changing to SMB3 had no effect. Purpose of this post is to see if anyone else who upgraded to 2004 is also running into this problem.

EDIT #2: I verified that other Windows 10 computers on my network (same version) can still access the server shares so not sure what's up with this one PC. It's doing some other strange things as well, like not connecting to port 80 on this same server when using its public DNS.

Start button --->Run ---> regedit ---> enter Then go to: Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters

Open folder "Parameters" and there you'll find "AllowInsecureGuestAuth". Double click on "AllowInsecureGuestAuth" and change "Value Data" to 1 instead of 0. Clik OK and that should be all.