Reply to RCA's, Cartridge Connection, or Stylus?

So everything worked fine when I played this weekend like usual, but then I go to practice a bit toevening & I got a problem. Don't know what the solution is though. I use TSD2, with Technics M3D, MK1 Timecode, and Ortofon DJ cartridges/needles (the blue ones).

My problem is that a track would not play in Traktor. The track would just keep skipping over the same 1 second part of the song at the beginning and the needle was not moving on the timecode. The software says left channel missing so I checked to make sure my rca's are plugged in all the way. It still skips. So then I change the stylus and seems to work a lot better, though the 2 circles in the calibration still sometimes seem to look like they are bending or "folding" a bit at times. But Traktor no longer said anything about missing left channel after putting the new stylus on.

The weird thing is I tried switching timecode records from deck to deck with the same results on the deck that wasn't working right (still skipped on different piece of timecode), but they both work fine on the other deck, and even tried the stylus I just replaced on the other deck and calibration worked fine.

I would say the needle I just replaced I have only used about 10 months. That seems kinda short lifespan to me. How would I know for sure when to replace? My other thoughts are maybe rca's might need to be replaced - they are the originals from 99, though they really probably have just under 500 or 600 hrs on them. The one other thing I tried was cleaning the connection between the tonearm and cartridge with a dry q-tip, though that seemed clean in the first place.

Any ideas or thoughts here? I can't figure out why one table plays fine with the exact same timecode and needle while the other suddenly does not. Thanks to all who took the time to read this probably longer post then it should have been.