What version of firmware is your Conbee running? It is impossible to upgrade the firmware of your conbee stick when Deconz is running in a HASS.io container, even though there is a button “upgrade firmware” visible in Deconz, the button does nothing.
Try upgrading your firmware of your conbee stick to the latest version by shutting down your RPi, pulling out the Conbee, and plugging it in a windows, mac or linux machine, and do the firmware upgrade that way.
Your network will stay in tact, think of the conbee stick like a wifi stick, there is no config on the stick itself, it is just a hardware device that gives zigbee capabilities to your operating system. All the config is on the machine it is plugged into.
I used to have similar issues, and first thought it was due to buggy integration. Turns out, I was running a 4 year old firmware on my stick that lagged lots of bugfixes.
Since upgrading last month, not a single device on my network became unreachable, and the network stayed in tact through several reboot of the RPi, things that would have definitely caused issues with the old firmware.