slow speeds with R11e-LTE6 / mANT LTE 5o replacement ?

Hi everyone,

I am experiencing unusually slow 4G speeds on netmetal ac2 with R11e-LTE6 (EU) and mANT LTE 5o. This antenna is supposed to have 5dBi gain.

By slow speeds I mean 25/5. The current stats are as following:

The operator is Orange Slovakia

A person in my other thread regarding this suggested using a higher gain antenna, but I have no idea which one. Can someone recommend if this is the right approach and would actually help ?

Thank you
Michael

check this thread/post LTE Antennas