Can I check if you are pairing the Zigbee devices next to the co-ordinator?
This often means mesh is not properly used (turn the coordinator OFF for >60 minutes to force a Zigbee mesh recalculation).
Even if your RF environment is really that bad, moving the co-ordinators won’t help coverage in a good mesh (only a slight reduction in latency). Look for the many posts here on improving mesh networks.
There were remote Z-Wave co-ordinators designed for hotel rooms powered over PoE, but not seen them on sale for some years (posted details in the forum before). Z-Wave networks typically “heal” regularly at 02:00 so the mesh gets recalculated.
Beyond that: