Rav4 EV won't charge on hardwired Siemens charging station

I have two Siemens charging stations, both 240V. The only difference is one is hardwired and the other is a plug-in.

I have owned my Rav4 EV for 1 month, and had no problems with charging the vehicle (except for configuring the departure schedule).

Until recently, the vehicle may or may not charge when connected to the hardwired unit. Two mornings in a row that I have tried to charge with the hardwired unit, the dashboard would show that it is connected to charge, but fails to charge it. However, when I tried in the afternoon with the same hardwired unit, it started charging immediately (The departure schedule on the car is set to charge immediately everytime). When connected it to the plug-in unit , it charges with no problem. I own a Nissan Leaf and both chargers work perfectly fine.

I'm wondering what is the reason that the hardwired unit charges the vehicle occasionally? And why now? It was working just fine the past month.

Are they both the same generation of Siemens EVSE? There was both a firmware update on the older version (VC30BLK), and more substantive changes to make a newer version VC30GRY ? .

Suggest you call Siemens with the serial number of the one that doesn't work.