Could be as gator suggests. Turn signal originates in SmartWheel w/the switch, travels by wire to the SW control box, then to the Vansco. Output LEDs 5 & 6 are RH & LH turn signal on the Vansco CMM2820 module behind the plastic kick panel in front of passenger's feet. You can verify those w/the turn signal running. The "click" and turn arrow indicators on the dash are part of the Actia gauge cluster, and these receive their signal on the J1939 CAN Buss twisted pair off the Vansco.
If there is no Actia arrow & click, then i'd speculate the switch in SmartWheel is the culprit. If you have click & arrow flashing, then its probably the output from the Vansco or the circuit wire to the bulb(s).
Your "flasher" is a computer function in the Vansco, outputing a pulsed +12V in 3 locations, one on front Vansco (the plug pin corresponding to the LED6 output), and two on the rear Vansco (pins to the rear bulb(s) & trailer plug turn spade).
Baja-tested '08 2-slide 36'
Alpine: The Ultimate DIY'er Project