169.254.35.186/16 is a link-local (self-assigned) address which normally indicates something has failed at layer2 and prevents layer3 functions like DHCP from succeding .. i.e. you fell off the network.
Issues are unlikely to be from ConnMan as all it really does is instruct the wireless daemon (iwd) to start/stop connections. It might be worth seeing if iwd itself is the issue by doing a clean compile of LE with ye olde wpa_supplicant not iwd, the choice is configured in the distributions/LibreELEC/options file IIRC.