Tried to visit on May 19 but could not enter.
The M-CHARGE app indicated open 24/7, but that's not the case. The gate was closed. I reported the issue and the opening hours were updated in the app.
There was a ticket gate before the curtain, but that ticket gate was turned off and I was able to drive through. Luckily there was enough space further on to turn around when I found the curtain closed. I don't know whether those ticket gates are used anymore. There were parking tariffs posted on them but they might be out of date if they installed a parking meter instead.