Currently, the firmware does not implement logic to switch to the different antenna in the case where initial connection failure. The modem constantly tries to contact the opposite side on the same antenna port infinitely.
In my opinion, this could lead to a hazardous situation where the connection fails during one antenna failure. The subsequential connection recovery may not be successful because constant use of the accidental selection of the failed antenna.
Ideally, the antenna diversity algorithm should blindly swap the antenna after every connection init failure.