Hi Sunny,
Apologies, that was a typo. I meant to say we have never had Windwos firewall enabled. So that rules out that also.
We have just recently changed the network adapter from the VMware to the standard Intel adapter, but that hasn't changed things either.
Also to note, we have printers with a scan function that saves using SMB to a share on the same server. These also lose connection which does point to an SMB issue.
I believe we are completely out of ideas on our side. We have even replicated our network with a Server 2019 box and a Linus CentOS 6 box - but we are unable to replicate as that setup works fine.
We would welcome any and every suggestion you can think of right now!