All embedded COTS LTE modules that i could find work only with a clearance of the groundplane below the module.
Do you have a module that works over a groundplane, like your Trogona or Mica antennas? The module may have a larger height up to 8mm in order to get away from the GND and for better radiation in one half space.
If not, do you know a module from a competitor?
Thanks very much,