R19 and R62 are only for L1/R1.
You really need a scope to see if 2L and 2R are both acting right. Pad 1 and pad 14 of the connector there that goes to the Daughter (Flex) board. Should be a 500Hz, 3.2v p/p signal on each one if it's connected to USB. You can use a DMM, but that will only show you the voltage, but if pad 1 (2L) has 3.2v and pad 14 (2R) don't match, then that's a good enough test to let you know the issue is there, and that 2R line just runs straight to the MCU. So the 2R trace, the contact or the MCU is the issue.
If that signal (not just the voltage) is on 2R, then the issue would have to be on the R2 line, pad 17, and that also runs straight to the MCU, so it's the trace, contact or the MCU again.