I'm still checking wires and ohms and playing with the test light. But it seems the switch is bad.

Can you swap the wires side for side and see if you have the reverse situation?

Not sure but my RR did the same thing and it was the blinker switch in the column. I changed that out and all my lights work Good now.
I messed with wires, grounds, bulbs, etc till I finally figured it out.
If I turned on the opposite side blinker then the bad side lights would work like normal.
David

Mine just straight up doesn't work. I pulled the cancelling cam out and jumped things and read things. It looks like the switch. I'll get back to it this weekend, I hope. I have a little over a week to get the little things worked out for Columbus.