mzperxcalling In the end, I had to rebuild the home network to make it fit. The trick: do not mix nodes with global firmware and nodes with Chinese firmware: even if they seem to be working well with each other, they work better if only on or the other type of firmware you have. e.g. the new AX3000 nodes work well together with the old AX1800 nodes but only if both have either global or Chinese firmware. (and the maximum number of nodes supported? currently: 4)

mzperxcalling it went wrong after two months. not worth the money.

mzperxcalling turns out I mixed up the old ones and the new ones: old had 1200mAh battery, new has 750mAh, but the new one seems to have more reliable earplug charging level indicator.

mzperxcalling Since then the pairing problem got resolved. Once I successfully paired it with a Raspberry Pi (no pin or passkey was entered there either) it started to work with other devices as well. Also with those that were not successful earlier.