Low MCS with SRSRan_Project gNb SA mode with USRP_210_Luowave

[qmodem-tech]

Hi. I am attempting to achieve peak performance with the USRP Luowave B210 in 20 MHz n78 SA mode, and during my testing, I have observed a low MCS of around 17-18 and a maximum throughput of approximately 30 Mbit/sec.

Here are results from USRP:

Here is NSG instant view:

Here is my config:

Also, I noticed that the SS-SINR before starting the DL test is ~28-29 dB, and after starting, it's getting 7-8 dB.
Any ideas?