I've been working away on this problem. Its still happening.
I did re-install VMware also took the opportunity to upgrade v15 to v16. Made no difference. But it was useful to try that.
The only change I had made recently, that could potentially affect the network was to install Tunnel Bear. So de-installed that. Made no difference.
I have tried comparing network settings,via ipconfig, from when the connections are working to when not working. But I can see no differences. Also looked at Vmware services and Windows network-related services. All look the same when working or not working.
I'm running out of ideas now 