Hi
At this point my custom board is working as expected using the same antenna that came with nRF Feather thank you so much Jared for your help!
I am now looking for good options for a chip antenna which I can incorporate - which is as as small as possible and covers NB-IoT bands.
Any suggestions?
Thank you
Chip antenna for nRF9160 - NB-IoT application
Best thing to do is pull that antenna up on a site like Digikey and use the parametric search to find antennas similar to it. (Thats what I would do! )