Pi is shown as offline

Check whether the picockpit-client service is active on your Raspberry Pi. Please open a terminal and write:

sudo service picockpit-client status

This will give you the following output, if picockpit-client is active and working correctly:

service picockpit-client status, active (running)

Investigate the log output next. You can dump it to a file with the following command, to send it to us, so we can analyze the problem:

sudo journalctl -u picockpit-client.service -n 1000 > /tmp/log.txt
part of the log provided by journalctl