I do not know why it now works - after an afternoon of ignoring it and watching football, I came back, stopped and restarted the Google Cloud VM, figured I would try ReaNinJam, which worked, so I went back to Jamtaba to confirm the difference, and now Jamtaba works again also. At this point I do not know what was wrong before.
At end of month I will probably switch to a paid VPS - if anyone has recommendtions that would be great - I am considering
https://greenhost.net/products/vps/ - mighty cheap, supposedly ethical.