AM3 Athlon II 260u (1.8Ghz!) 3615xs system has updated from 7.0.1-42218-2 to -3 ok.
Gen7 microserver 3615xs has been operating 24/7 since September on 7.0.1 and also updated ok to -3.
* Both have NC360T nics installed and used as lan1 although tinycore installs appropriate drivers for the onboard nics, both are recognised in DSM and are usable.
* Both now using tinycore loader, Gen7 previously using the original thorgroup loader since August.
Installed 3622xs+ 7.0.1-42218 ok on the AM3 system to test but didn't update any further and reinstalled 3615xs, "all files and settings" option.
* The section under Control Panel/DSM Update/Status shows correctly on the 3615xs (your DSM version is up to date) but shows "unable to connect" on 3622xs+.
From the release notes for 7.1:
"For the following models, DSM 7.1 will be the last upgradable version: .....DS3615xs"
It will quarantine two of my real synos as well 😒