status/network: Disconnect signal handler on destroy in NMConnectionItem
Otherwise this can trigger _sync() calls after the objects it is trying to update have been destroyed.
See #1704 (comment 1070296) and #4013 (closed). I couldn't test this locally though , because I don't have multiple networks available to switch between and trigger this.
I think this should work to trigger the bug (not sure if all steps are necessary though):
connect to wifiopen status menuenable airplane modeenable wifi againopen status menuswitch to a different wifi network
Edited by Sebastian Keller