There are two variants of this plug. The model 72922 has been reported to work with Xiaomi / Aqara devices - for the most part, but model 72922-A definitely doesn’t work with them. If that “-A” model is the one you have, then I’m not surprised by the behavior you describe. For most ZigBee repeater devices, if by some luck the repeater device does allow Xiaomi / Aqara devices to stay connected, then there can be issues with the repeater not passing on messages from Xiaomi / Aqara devices. I’ve witnessed it with a Securifi Peanut Plug I tried out, and I’ve read of the same behavior with the Sylvania 72922-A Smart Plug.
Although this may seem like a good way to avoid Xiaomi/Aqara sensors from routing through an incompatible repeater, unfortunately it isn’t, because by design, ZigBee devices may choose the best available route to connect through, and that route can change at any time as conditions or the topography of the network change. For the vast majority of ZigBee devices, users have no control of how, when, or where they choose to connect to any particular repeater (or directly to the hub).
Again, I have witnessed this first hand, using an XBee module to view the map of my ZigBee network, and watched as some Xiaomi / Aqara devices decided to move to a new repeater device I added. On the other hand, I have read that with some Xiaomi / Aqara devices, they seem to be stubborn in deciding to change over to a repeater with a stronger signal, after the user moved them to their install location. The end result of that can be a weak connection to the hub and the potential for those devices being dropped off the network.
For best results, ZigBee devices should be paired in their install location so they connect via a nearby repeater if the signal is strong enough (and if that repeater has available slots for more end devices.) The only way to confirm the route they have decided to take is with an XBee module (see this thread for more information.)
I would recommend that. I have one TRADFRI Outlet and it works great as a repeater for Xiaomi / Aqara devices on my Hubitat hub’s network (which works pretty much the same as a SmartThings v2 / v3 hub’s ZigBee network) , and plenty of Hubitat hub users have found the same.
I would highly recommend reading this thread I started over on the Hubitat Community Forums which contains a lot of very helpful information on keeping your Xiaomi / Aqara devices happily connected to your ZigBee network:
In the least, make sure to read through my opening post of that thread.
To my knowledge, only the XBee ZigBee modules can be configured like that. All other ZigBee repeater devices are “hardwired” with their particular settings.
It would fix it for the most part. As I understand it, if the ZigBee network was down or inaccessible long enough, Xiaomi / Aqara devices would be dropped and then wouldn’t rejoin when requested.
Also, adjusting that end device timeout would not fix any issues that some repeaters have in simply not forwarding messages from Xiaomi / Aqara devices (as I mention in my reply to @rumrunner424, above.