I have your exact setup. Have you done any tweaking? What channel are you on? All I can think is, I have thick concrete walls. Changing battery also didn’t help.
I haven’t done any channel optimisation so far, I probably should do. I have the P version of the Sonoff Zigbee dongle, I haven’t tried the E version.
I’ve also been careful with picking router devices. I’ve tried to avoid router devices that have poor reported compatibility with Aqara. There is a page/thread somewhere online where people were compiling lists of devices that do or don’t play nice with Aqara. IKEA devices apparently work very well with Aqara, I’ve been using their smart plugs wherever I can.
My Zigbee network also improved a lot when I set up some IKEA plugs in the loft. My house also has thick walls, but it seems Zigbee signal can propagate more easily through ceilings/floors.
Using quality brand batteries also seems to help a bit, at least from a battery life point of view.
IKEA devices apparently work very well with Aqara
When it comes to zigbee devices, don’t combine the aqara wall switches with large (4 buttons) ikea remotes.
The wall switches tend to execute the commands from the remotes instead of just routing them to the coordinator.
My Zigbee network also improved a lot when I set up some IKEA plugs in the loft.
I have similar experience with the ikea bulbs. More of them I connect, more stable the whole network gets.
