Playback shows choppy/dropped frames after rendering project...

I submit MXF files to two different broadcast networks. Both require almost identical video/audio formats. 22 minute long shows. I'm equipped with a MacBook Pro M1 (2020), 16GB RAM -  (Monterey 12.6.2) - FCP 10.6.5

Each render I perform ends up with a MXF file that plays back with some choppiness. Like it's dropping frames. The video file shows it's the same length in time when you import that rendered MXF file into FCP. 

Show "A" is less motion graphics heavy. Show "B" is more motion graphics heavy. Both can be problematic... but I would say show "B" gets even more choppy/dropped frames. Points toward hardware not being robust if you ask me. But I know it's not that simple. 

I've been going both routes.... rendering in FCP and in Compressor. Basically the same results. 

Approaches to troubleshooting:

1. Render out each segment (4 total segments equalling 22 minutes as a whole) individually as Apple ProRes 422 (default). 
Piece them back together in a separate Library...  render out that library as:
MXF (OP-1A) XDCAM HD 4221280 X 72050.0 MBPS8 channels of audio( even if only two are active, all 8 need to be present)59.94 Drop Frame TC with a 1 hour start

 choppy/dropped frames still produce.

2. Tried it on my wife's MacBook Air M1. Actually produced a little bit better of results. Still choppy/dropped frames.

3. Trying Intel iMac right now.... results not available.

4. Opened a new user account, signed in and repeated the first example (1. Render out each segment...). Still choppy/dropped frames. 

Is my equipment not robust enough?

Any ideas on troubleshooting are appreciated. Thank you.

Are you working off of an external drive? If so, what make/model/interface?

Also, when you play back a particular deliverable and witness the choppiness, is it choppy in the same spots consistently, or does it change? If it's consistently in the same place(s), can you step through those frames to verify that they've rendered?