Fermax 8022 Error - Sometimes opening works, sometimes doesn't

Hi, a while ago I posted here about Fermax 8022 not working https://community.ring.com/t/ring-intercom-fermax-8022-not-working/197346 After some talks with the engineering team they seemed to fix the issue by extending the signal or the time of the opening signal. It wasn't working at all and ended up working propelly for 2 months... Until 2 weeks ago. I checked the cables again just in case any cable was loose but it's everything in place and I did re-connect them all just in case. I did re-config the device again to make sure everything works as should (and it does) However from time to time I keep getting "Error" on the app while trying to open. Sometimes it does open (in some strange cases it still signals "Error") and most of the times it doesn't open at all. Cables are propelly connected, device was re-configured (this improved a bit the opening).  Maybe I need a custom firmware or my device is faulty?