Hello,
Carrier Aggregation capabilities are limited by the internal modem chipset, thus it is not possible to change them via an update.
However, I’ve noticed that you have locked onto the B3 cell which supports 10MHz bandwidth, while the B3 cell acting as a secondary supports 20MHz. Could you try locking onto a cell with EARFCN of 1501 and check if that makes any difference? Primary cell can usually impact the overall network performance and stability greatly.
As for only 3 bands showing up in the WebUI, this is a know visualization issue, and it will be addressed with the 7.5 release.
Just in case you were referring to band lock, and not cell lock, here is a short manual for band locking on RUTX50: RUTX50 - Locking 5G-NSA CA bands manually - #4 by Daumantas
Best regards,