Usrp reflections


I know, usrp manual says, that you don’t need TX/RX antenna, but how
about reflections from used TX port and also unused TX/RX + RX ports?
Because i get all the time “failed to set initial frequency” error, if I
run script (probably because of interferences usrp can’t
synchronize both d-boards [in this case RFX-1800])

Is it really OK, that unused ports don’t have terminating resistor and
TX/RX without antenna?

here are quotes from manual:

Do not use a transmit antenna. Plenty of power leaks out of the USRP for
close-range testing. In fact, using a transmit antenna causes a lot of
transmit power to couple into the receiver, reducing receiver
performance and limiting uplink range

Do use a receive antenna. Remember that GSM uses active uplink power
control. The more sensitive your receiver is, the less power the BTS
will need to request from the phone.