Soldato
-109dBm on 4G B1 (2100Mhz) I'm guessing dBm is RSRP, with a -2dB SINR so anything over -100dBm is cell edge / disconnect territory and you want positive SINR figures. -92dBm on 5G N78 with SINR 12dB is low. All not looking ideal tbh. Any chance you can select a 4G bands on the Router? Changing to B3 (1800Mhz) may help (will be slightly slower speeds but should improve signal strength).