Band Locking vs CA

[matrx10503]

I was under the impression that Carrier Aggregation would gain me speeds, but so far it has decreased in all scenarios.
Ok as a baseline I use a OnePlus 6 phone (cat 16, 4x4 mimo). (and just as a reference with AT&T I can get about 40-60Mbps consistently in 2xCA mode.)
So I have a Tmo setup. So bands i'm primary dealing with from my tower are: 2,4,12,66,71
In the OnePlus 6 and tmo sim, I get 3xCA 4x2 mode from the tower, bands 2,4,12, ~20Mbps.

Now, router setups. I have mc7455 that does 2xCA bands 2,12 mostly and rarely 4,12 ~15-20Mbps
When I band lock 4 I get the best speeds of 25-35Mbps. Bands 2 and 12 average 10-15mbps

I bought a mf288 (Cat 16 4xCA, 4x4 mimo) for cheap. I have basically no way to know what bands its on nor what measurement the signal is in, I assume RSSI but I use RSRP as my metric of reference since dealing with LTE. I only have a 2x2 external mimo external antenna. And the router has paddle antennas.
I don't know what happens when the external antenna is hooked up as far as 4x4 mimo. But I can get 3 bars out of 4 signal.
I can see LTE when idle then when I do speed test or video, LTE+ is surely kicking in. So it is aggregating. My guess is 2+4+12 like my OnePlus. I doubt its doing 4xCA.
Speeds have been 10Mbps max so far.

Edit:
Just did a late night test to try and minimize the tower load variable. Using the mc7455, I am currently on 2xCA bands 4,12. (I did tweak my external antenna position to get 4+12 primarily aggregating together instead of the slower 2+12)
Speed test is now ~50Mbps. Which the math pretty much checks out: band locked 4 speeds+band locked 12 speeds=CA speeds.

I hooked the mf288 back up with hope. I tried with just my external mimo antenna with no paddle antennas and external+ with paddles hooked up. Shows LTE+ kicking in, Signal goes from 1 to 3 bars max. Speed tests never got above 15Mbps.
So my guess is that its using the strongest signal band I receive as primary, which is 12.....but in fact is also the slowest of all the bands. Who knows what CA or mimo mode its using.

Even though I can't confirm with the mf288 as I intended, I do feel better now about possibly putting together a proper 3xCA or 4xCA capable setup to benefit me.

[Didneywhorl]

Super hard to say. I'm not familiar with the mf288. Who makes it?

[matrx10503]

ZTE....it's basically the companion to the Nighthawk M1 that was sold to Bell/Rogers (Canadian carriers).
It uses the Qualcomm MDM9250 chipset