We have been seeing this with PMP430 SMs connected to PMP450 AP I just shared our findings with you here, and cambium could recreat the problem and they are investegating the issue as of now.
I ran baselines with 4 different configurations.
AP on 13.2.1 / SM's on 13.2.1 (PMP430 Interop Mode SISO)
AP on 13.2.1 / SM's on 13.2.1 (PMP430 Interop Mode MIMO-A)
AP on 13.2.1 / SM's on 13.1.3
AP on 13.1.3 / SM's on 13.1.3
First of all there was no change in the upload baseline results between Interop Mode set to SISO or MIMO-A with the AP and SM's running on 13.2.1.
Second, I found that there was a significant increase in upload with the SM's on 13.1.3 over 13.2.1. The firmware version of the AP made no significant change to the upload baselines. Typically the increase was around 2meg or more.
One thing that I did find was that when AP and SM's were both on 13.1.3 there was a drop in the download baselines on most of the 430 SM connections. The download was cut in half with some. Once the AP was upgraded to 13.2.1 the download returned to normal. I ran the baseline test 3 times with the same results.
In conclusion, the best results were when the AP was running on 13.2.1 with Interop Mode set to SISO and the SM's were on 13.1.3.