Based on proposed solutions at: What causes some Network Drives using SMB no longer connect to macOS Catalina?
I have edited the /etc/nsmb.conf which worked for about seven (7) days, and now nothing. I verified that the edited lines are intact after a system update from apple.
I am using Samba version 4.7.6.
On server side I set the smb.conf file in GLOBAL settings to include the line:
min protocol = SMB2 (I have also tried, min protocol = SMB3) different server, same result (no connection).
somewhat at wit's end. May have to roll back from Catalina.
I can access the servers from android devices and Windows 10