When I start simply with bitcoind and stop with bitcoin-cli stop everything works fine.

But if I start bitcoind with sudo systemctl start bitcoind and I made this /etc/systemd/system/bitcoind.service:

[Unit]
Description=Bitcoin daemon
After=network.target
[Service]
ExecStart=/usr/local/bin/bitcoind -conf=/home/bitcoin/.bitcoin/bitcoin.conf -pid=/home/bitcoin/.bitcoin/bitcoind.pid
# Creates /run/bitcoind owned by bitcoin
RuntimeDirectory=bitcoind
User=bitcoin
Type=forking
PIDFile=/home/bitcoin/.bitcoin/bitcoind.pid
Restart=on-failure
# Hardening measures
####################
# Provide a private /tmp and /var/tmp.
PrivateTmp=true
# Mount /usr, /boot/ and /etc read-only for the process.
ProtectSystem=full
# Disallow the process and all of its children to gain
# new privileges through execve().
NoNewPrivileges=true
# Use a new /dev namespace only populated with API pseudo devices
# such as /dev/null, /dev/zero and /dev/random.
PrivateDevices=true
# Deny the creation of writable and executable memory mappings.
MemoryDenyWriteExecute=true
[Install]
WantedBy=multi-user.target

two things happen that I don't understand. First, despite having /home/bitcoin/.bitcoin/bitcoin.conf like this

printtoconsole=1
logips=1
maxconnections=40
maxuploadtarget=5000
dbcache=100
maxorphantx=10
maxmempool=50
txindex=1
rpcuser=bitcoinrpc
rpcpassword=Postfach24
rpcclienttimeout=300
server=1

there is no output to the console if started via systemctl.

Also, if I check for messages with tail -n 100 -f ~/.bitcoin/debug.log I see rewind blocks a lot and the process seems to loop.