Change of device connection too easy?

Went out trail running for the first time with the new t-beam and lora32 in the top room for range testing. Got about 1.7km before losing connection. However one worry was complete loss of all connections. Eventually found out that it had changed device to my car, must have happened as I popped the phone back in my vest. I suppose a rare event but easily done in the field. It had changed screens as well so not immediately apparent.

On another note…if I plan on placing high up repeaters is it worth upgrading the antenna or not worth it if the carried device has the standard antenna? Be good to get over 5 mile los for the mountain valleys