I've recently bought a strongish directional antenna for my LTE modem,
and the cables to connect to the modem.
But when I connect it to my Sierra Wireless 7455 card (which is working fine with small omnidirectional antennas, connected to my OpenWrt router) the connection drops and it does not come back.
When I connect the same thing to my Huawei B310s-22 LTE modem (which is a full device with its own web interface and ethernet and wifi capabilities, it's not running OpenWrt of course) then it works correctly.
Another weird thing is that while this antenna claims it's MU-MIMO whenever I connect both cables the signal intensity drops dramatically, so I suspect that this "dual antenna" is just supposed to be used one at a time, depending on how the antenna is oriented (horizontally or vertically, as that's what is labeled on the connectors).
I might just saw the metal plate and make two separate antennas out of this thing later if I figure out why it's not workign with the Sierra Wireless modem card.
I'm suspecting that this antenna requires some signal booster circuit that is present in the Huawei full device but is not present in the Sierra Wireless M.2 card.
Since I'm a goat in this field and Google is failing me, does anyone know what is the problem?