RM520n-GL Works in ECM mode but if signal is lost, it wont reconnect!

Hey!
When I run the modem in RNDIS mode, if I remove the sim card, and re insert it the modem will re-establish the connection. But in ECM mode I need to reboot the modem for it to detect the sim being inserted. Is this normal?

Also and this is my big problem! If in ECM mode if I drop the cellular connection cause of reception it will never reconnect again when signal is resumed. Only way I have found to get the modem to reconnect is to do a full restart of the modem.

Modem is connected to a Waveshare usb-to-m.2-b-key board on a Orange Pi 5 Plus running ubuntu and the custom software needs the ECM mode to see the modem. In RNDIS the module shows up as a WWAN device and wont work in the bonder.

Any help would be much appriciated!

Thanks!