I believe I have finally resolved the issue with the GSM daughter board and/or antenna interfering with my GPS. I replaced both and it seems to be all good now.

Interestingly, I found this nice Antenna that has GSM and GPS (with 2 well-labeled tails that are compatible with the OVMS connections).

It seems to be working well and is much neater to replace (I snaked it up through to the speaker+air cover on the front dash area).

//.ichael