Twisting / shielding CRSF

Having some problems (intermittent loss of RC signal) with CRSF receiver mounted at the end of one of the wings. Wires connecting receiver to flight controller are not twisted, nor shielded but run right next to power lines feeding the motors (located in wings) and close to the ESCs. Is that likely to be the problem i.e. not twisted or shielded? Thanks for any thoughts.