Yeah that could very well be one of the root causes of your problems other than EMF/EMI/RMI interference. There is no other way around it. You need to disable all dumb switches connected to Zigbee Router lightbulbs or replace those lightbulbs with models that are not Zigbee Router devices.
This was recently explained in more detail to a other user here who understood the problem but did not accept the only possible solutions → Stop Zigbee Mains powered device from being a router? (ZHA)
Maybe the Philips Hue Bridge handles recovery in that scenario better but the fact is that using dumb switches to Zigbee Router lightbulbs is dumb, it goes against the architectural design of a Zigbee network mesh and breaks the technology.
Hell, in my opinion, manufacturers making Zigbee lightbulbs that are Zigbee Router devices is stupid as of course many users will make this mistake without knowing it. If you read on Sengled website they specifically mention that this is why their Zigbee lightbulbs are not Zigbee Router devices → https://support.sengled.com/hc/en-us/articles/115010871308-Do-any-Sengled-Zigbee-devices-act-as-Zigbee-repeaters
That is only an indicator of radio noise (i.e interference) which is just one of many parameters and one that is usually among the easist to fix when you understand that interference is a serious problem for Zigbee as all you need is to relocate the Zigbee Coordinator away from all sources of interference and maybe switch either WiFi channel or Zigbee channel so that they do not conflict. Again read and follow these tips → Zigbee networks: how to guide for avoiding interference and optimize for getting better range + coverage
Those errors mean that Zigbee communication messages failed to be delivered to one or more devices, and that can be due to either interference jamming the signals or you switching of Zigbee lightbulbs acting as Zigbee Router devices with dumb switches.
The root causes of these problems can not be fixed with software configuration so I think it is now time for you to understand that you need to change your mindset and grasp that you need to take some actions, whether you like the idea of them or not.
