Hi Luis. You can calculate what to expect in terms of PHY performance based on the per chain SNR: http://backhaul.help.mimosa.co/backhaul-faq-snr-mcs
In this case, the Dashboard MIMO Status panel shows that the SNR ranges from 17 to 27 dB, and that the MCS rates are fluctuating between 4 and 5 based on the interference levels. Tip: while tuning, look at these values on both sides to determine which side of the link could be improved.
The Dashboard Performance panel also contains the Packet Error Rate (PER), which is not shown in the screen captures, but would likely explain the PHY rate asymmetry.
For the reasons above, you may want to try a single 80 MHz channel, which benefits from an additional 3 dB internal signal processing gain, to achieve higher MCS and more symmetric PHY performance.
One or more streams may not be used if the PHY can not support them in one direction or the other.
The signal target is calculated based on Free Space Path Loss and the EIRP from the AP. If the antenna gain or GPS coordinates are inaccurate (or if the actual gain is different on each side), then this value will be affected.
We recently published an RF Tuning Guide that contains links to more information about each of these topics: http://backhaul.help.mimosa.co/backhaul-installation-rf-tuning.