Hello, off course can you use 2 antennas, if you have the space. I prfer to use Mars antennas with CPR Case on the back and dual polarity.and you can not put two antennas with opposite polarizations? vertical and horizontal sectorial?
This is already under invertigation with Mikrotik. The problem is not a Mikrotik-problem in special. I have expierience with WPA-PSK. This happend often.WPA and AES in 2.9.0 work fine !!!
In 2.9.1 and later not work !!!!