I have massive issues with file shares. I'm on the latest beta. Initially, when accessing share - everything is fine, however, once you start to write to it hangs and disconnects and (!) all the network access hangs, including internet etc. The only solution is to reboot! This is just driving me crazy, I never had macos Beta with issues like that!
PS. And no, reloading SMB kext doesn't do anything. And yes, Catalina laptop and other windows machines on a network can access the same share just fine.