60fps playback issue

[npapaleo]

I recently started working with 60fps video, and I'm finding that no matter the codec, pro tools will not play the video back correctly. The first 3 to 4 seconds plays back as black, followed by what should've been the first frame, shifting the whole video off 3 to 4 seconds. The monitor and video output card do not seem to matter. I've recreated the issue playing back on my main (HP z27) monitor and also when sending it through an AJA i/o xt.

I've tried DNxHD, DNxHR (mxf), ProRes 422, and H.264. What's weird is if I import the same video into Video Slave and lock it to pro tools it plays back correctly. I'd rather not have to purchase Video Slave to perform a function that Avid says works natively.

Mac Pro Late 2013
3 GHz 8-Core Intel Xeon E5
64 GB 1866 MHz DDR3
MAC OS 10.14.6
Pro Tools Ultimate 2020.5