Metal slap / grind in 2nd and 3rd gear WITHOUT even disengaging clutch

[JakeN]

Hi all, I've been experiencing shifting issues with the manual transmission in my 370Z, yet they're unlike the typical clunkiness / grinding of 2nd gear that's familiar to these transmissions. I drive a 2017 Sport Tech 370Z with 60,000 miles on it, and I've been driving it with the rev-matching tech turned off since I picked the car up on the used market. The issue is as follows:

- I feel unpleasant metal-to-metal contact in the shifter after completing the shift throw
- The contact occurs before I've even begun releasing the clutch
- The contact can be an audible click as I finish the throw all the way or a grind felt through the shift knob, but it doesn't sound or feel like I'm grinding gears
- Sometimes the issue occurs in two stages, one as the shifter passes through the neutral gate into the required gear and the second at the end of the throw
- Replacing the transmission fluid has not alleviated the issue
- The issue only occurs if the car is running and being driven
- The issue is most prevalent in 2nd and 3rd gear
- Downshifting / upshifting to these gears does not make a difference
- Shifting harder has historically alleviated the issue, yet now that makes no difference
- Temperature does not seem to play a role in the issue
- The issue has been continuing for ~5,000 miles

Based on the research I've done and my testing, I'm slightly at a loss for what could be occurring. While I'd like to point to something wrong in the shifter linkage, I find that hard to explain how I cannot replicate the issue when the car is off. My only theory is that something in the shifter linkage could potentially be contacting some rotating assembly in the transmission. I don't think this is a syncro issue, considering the clutch is fully depressed when it occurs. Any advice would be fantastic, because I've reached the depth of my knowledge for transmissions. I've tried to encapsulate anything people would want to know about the issue, but I'd be happy to provide more information if anyone has any questions