A big Part from my systemd daemon.log which maybe already shows the issue.
Tor never bootstraps, so systemd restarts it.You can confirm by checking your systemd logs.
Is your network connection fast and reliable enough?
Tor needs a lot of connections.Does your pi support 6000 simultaneous connections?Does your router support 12,000 simultaneous connections?Most home routers don't.
I'd really need to see your logs to work out what's happening.
I need to see what happens between log lines like this:
Feb 16 23:37:49.000 [notice] Bootstrapped 0%: StartingFeb 16 23:43:45.000 [notice] Tor 0.2.9.14 (git-a211f886ad759cab) opening log file.