Sorry to hear you’re having so many problems. My system is largely z-wave, not zigbee, so it’s not totally comparable… but I certainly don’t have problems as frequently as you do.
I’m sure support has talked to you about this, but if all you have in your system is zigbee bulbs and zigbee motion sensors, you don’t have any devices in your system that repeat commands. So instead of having a robust mesh, you have a weak mesh. Try adding some plug-in devices.
For your lock (which I assume is z-wave), try moving your hub closer (within a foot) of the lock, and then excluding and adding it to your mesh again. Once that is complete, move your hub back to its normal location. If you still have problems, try adding some z-wave repeaters between your hub and your lock.
For your door and window sensors, try introducing a small (3-4mm) gap between the magnet and the sensor. Most sensors tell you the magnet should not come in direct contact with the sensor.