It might be worth doing a factory default reset on the AP because that can often clear odd join problems.> I wouldn't want to lose access to it, so I'm looking for a reliable and safe solution.That's why you get it working with 1 or 2 APs of each model ...
10.6.1.5 IPv6 Address... fd10:6:1::5 Last Reset... Software reset System Up Time... 10 days 5 hrs 45 mins 40 secs System Timezone Location... System Stats Realtime Interval... 5 System Stats Normal Interval... 180 Configured Country....