Test on the phone at home outside? Speedtest made over WiFi, so from the network of the MR6400 router with these antennas, do you at least know what LTE band this router connects to, what BTS? By the low UL, it can be assumed that the signal parameters on it are weak. The phone connects to LTE800 on BTS NetWorks Przechlewo, residual signal parameters, LTE1800 from this base station is not shown in the neighbors, apparently trace range or no coverage on this band. The station works in the LTE1800 + 800 aggregation, i.e. on the 20MHz band in the aggregation, I would like to see these 120Mb / s under BTS on a speedtest made between 19-23. The NetWorks infrastructure is very weak, naked base stations are based on 10MHz on LTE800, only the naked one in Przechlewo got another 10MHz on LTE1800 so it works somehow, no information about your location but it is obvious that you do not live in Przechlewo and you are quite far from the station.
Helpful post? Buy me a coffee.