Premier Pro 2023 dropping frames when sped up

Hi guys,

This is an issue that I've had since I've updated PP on a Brand new mac and I cannot find a solution

Please see attached screen recording, which shows clip smooth at 100% but dropping frames at 120% (rendered)

System Info:

Macbook pro 14" 2-23

Apple M2 Pro chip

16 gb RAM

OS Ventura 13.5

Premier Pro:

Version 23.4.0 (Build 56)

Media Type:

4K - DJI LOG H.265/264 - 29.97fps

Sequence Settings:

Square Pixels 1.0

29.97fps non drop frame timecode

apple prores 422HQ

What I've tried to solve the issue:

Changing time interpolation

Assuming different frame rate and adjusting sequence settings

Changing codec in sequence settings/preview format

Tioggling Bit depth/Render Quality

Rendering footage

Nesting Footage

Converting H.265 to 264

No matter what I try, premier skips frames as soon as i adjust the clip speed (both in premier and once I've exported). This issue doesn't happen when using an older version of PP on my old 2015 mac. 

The same issue happens when I upload footage from my gopro.

This is all dynamic drone footage and the skipping frames is painfully noticeable. When I speed the footage up in CapCut, I don't have any problems but it's impossible for me to edit properly in that app. 

I'm a bit of a newbie and have tried to explain things as clearly as possible, If there's any other detail you need, please let me know as I've spent hours trying to sort this and I just want this issue dealt with.

Thanks

Shaun