@robertoj, on the first ssh connection it asked me to delete the previous key and I did ,then it asked me for the password which I re-entered and it let me in.
As far as docker is concerned it has duned very well for a few years with portainer, minidlna,a tor relay , and deluge;managing the reserved storage it always worked then something broke , maybe due to an upgrade , and problems arose. Now I installed this old version of armbian as suggested by igor and it seems to be working fine since 24 hours.