Some TVs have problem with "3:2 pulldown" other it's "24/48Hz"...
I see the same problem as you with my Samsung here using Kodi but using a Samsung Blu Ray player (23.976 fps) movies are displayed correctly.
What i can suggest you is when your TV is switched to 24p mode, go to your TV's menu and try different combinations starting with;
-Film mode(Cinema smooth/Auto/Off)
-Motion Judder Canceller(Off/Standard/Smooth)
If none of those is correcting your problem, like in my case, you can try this below, these are my settings when using LibreELEC/Kodi.
In Kodi;
-Display - Refresh rate: 60
-Videos - Adjust display refresh rate: Off
-Videos - Sync playback to display: Disabled
-Movie's Video settings - Deinterlaced method: Temporal/Spatial
-Movie's Video settings - Video scaling method: Auto
-Movie's Video settings - Post-processing: Enabled
-Movie's Audio and subtitle settings - Audio offset: 0.000s
In TV
Film Mode: Off
Motion Judder Canceller: Off
With these settings my screen is staying in 60p mode but i have no problem with stuttering, dropped/skipped frames or audio sync.