Not all Zigbee devices are created equal. Your choice can contribute to mesh instability as much as other factors.
This post lists devices and combinations of devices that are known to cause issues - please add to it if you have experiences to share.
The first entry below can be taken as a template.
Note: This post is a wiki - you can edit it to make additions or corrections. No need to do it in a reply.
Moes mains powered wall light switches (UK)
Brand: Moes
Model: ZS-B-EU2
Link to exact product: Moes Switch 2 Gang EU/UK ZS-B-EU2 Zigbee compatibility
HA Integration: ZHA/Z2M
Date 28 April 2024
Comment:
Available in 1 2 and 3 gang versions. The 1-gang version is fine, but the two-gang model drops off a ZHA network about once a week. A little more stable with Z2M, but still an issue. More than one device tested.