My setup is also via Ethernet.
I had to reboot after uninstalling connman.
As I also appeared to have lost connectivity.
After reboot Ethernet connectivity was restored and all was working well.
Did you do a fresh install of bullseye or also upgrade in place like me?
I’m fairly convinced my issue is due to upgrading to bullseye in place rather than fresh install.
In my case Connman was not interacting well with some other parts of bullseye and network management. Your case might be different though. So perhaps there is an incompatibility with deconz.
At least we know now one of the actors contributing to the messages.
Further for me somehow it was the cause of my reboot issue. I tried swapping power supply’s. But that did not fix things. Only removing connman allowed me to properly update my rpi to latest kernel version. Have no idea why connman being installed would have blocked the update to latest kernel.