Joelin - Your signature line doesn't contain your equipment details, so I made some guesses:
Guidescope - ZWO 60mm, 280mm FL
GuideCamera - ZWO ASI120MM
OTA: 8" Celestron Edge HD + v3 Hyperstar - FL 400mm (aperture 200mm)
Imaging Camera - ZWO ASI1600MC-C
Guidecamera image scale - 2.76"/px
Imaging Camera image scale - 1.96"/px
You noted that the ASIAir is set to dither by 5 guidecamera pixels. That means that your imaging camera is getting dithered by 13.8 arcseconds or 7 pixels. IMO, that's a massive dither with your setup, and it's likely that you mount is taking an inordinately long time to return to the target after such a large displacement. I would suggest that you time the return-to-target with your mount. You might find that you just can't use a dither that high with your particular setup.
And as Jon notes, it's the dither frequency and dither randomness that also makes a large difference, not just the dither magnitude. You could potentially test this by setting up your gear and taking 20 10-15 second frames, dithering between each frame, then blinking them in PixInsight. If the ASIAir software is setup correctly, you should see the stars in a "blink movie" move around randomly, and by different amounts with each frame. If you find that the direction is random, but the amount of displacement is the same between each frame, I'd say you could back off your setting to about "3", which would presumably be dithering your imaging camera by about 4 pixels. That might help with your mount's recovery time.
If you find that the dither direction is not random, that's actually a software error - a dither in one direction only really won't help reject artifacts.