I have about six light switches ZBMINIL2 (and plan more), which have issues with ZigBee2MQTT & ZBDongle-E controller: the switches work, but every few minutes they leave the network and reconnect immediately.
Interestingly, all of the ZBMINIL2 eventually connect to router TuYa TS011F_plug_1 and work just fine. They seem to prefer the TuYa router even that the link quality is lower (50) compared to link quality with controller (190).
I think it might indeed be because the E variant of that dongle was only in ‘experimental’ support with Z2M, but works fully with ZHA. But that info might be out of date.
To the best of my knowledge, support is still indeed “Experimental” for the EZSP-based sticks with z2m. I recently tried to move from ZHA on Conbee II to z2m on ZBDongle-E but had so many issues that I ended up with z2m on Conbee II.
I’ve ordered a Dongle-P and will reflash my Dongle-E (x2) with Router firmware and put them in a couple of strategic places around the house to improve mesh coverage.
I hadn’t used z2m before, but won’t be going back to ZHA as the feature set is richer on z2m.