This smells like You have the same problem as I encountered.
see frozen sensors.
I also have reinstalled all the sensors multiple times with the same result (working for days/weeks/months and then suddenly it’s lost). But in fact it’s not really lost (in my case). The problem is that the data is not transfered anymore to Phoscon (and therefor home assistant).
You can check this :
in deCONZ (deCONZ application), when I click on the ‘+’ of the contact and then click on ‘on/off’, I can see the state changing in ‘cluster info’ in attribute ‘on/off’ (from false to true or vice versa) whenever I open/close the doorsensor.
I solved my problem by buying an SMLIGHT SLZB-06M.
After a month of working with this adapter, all my devices are still connected and working.
The setup took me some time, but once setup and working, it is worth the change (for me).