Conection problems after update v2.5.1.16

(I also have 2 RBS20 satellites).

After updating RBR50 and RBS50 today to the latest firmware (the RBS20 had them already) I have problems with connecting (at least) 2 systems: Rainbird (watersystem for garden) and BTcino (two way video doorbel).  Chance that both systems have a failure at the same time is very unlikely. They worked ok yesterday, so it is almost certain that the problem is caused by the new firmware.

Problem is that both systems simply do not connect (they appear to be in a sort of loop) and do not show in Orbi manager, neither in the Log. So I am puzzeled and do not know what to do.

Settings of the Orbi: parental control is off.  Security is WPA2-PSK [AES]. Rainbird is explicit that this security mode is supported, so - again - it is unlikely to me that the problem lies there.

One solution is of course may be restoring the RBR50 to factory settings... but that means quit a lot of work. Anyone has an idea? 

ps. For the rest (and the past) the system works fine, even "extremely fast".

Richard