Visited yesterday, charged with Shell Recharge RFID without any issue.
Both IchTankeStrom and the Shell Recharge app seemed to be having some issues with the live data yesterday. On IchTankeStrom the connector on the right was reported occupied, but this was frozen in place the entire day and there was nobody charging there. In the Shell Recharge app it continued to say both available despite my car charging since a few minutes.
It took a while to start the charge, even after authorizing the handshake took 1-2 minutes.
According to the stickers and matching with what little I saw of live data, 13620
is indeed the left charger and 13621
the right.
The signage says 2 spots are reserved exclusively for charging, max 3 hours.