The signal (SINR, RSRQ ...) as reported by the modem looks barely usable if at all. Can you check that your phone and the modem see the same cell ?
Have you tried another location for the antennas ? With one vertical and one horizontal ?
I had a similar issue (three cell towers in the same area, lots of interference poor SINR) and ended with two Yagi antennas now I am close the maximum possible in term of signal quality.