Having trouble with the FPS when exporting a gif.

So recently I made small looping animation of a head bop that's suppose to be moving at 70FPS  with there being a total of 28 frames in the looping animation. It looks pretty good, when in adobe animate. But when it comes to trying to export it, the FPS seems to lose some frames binging it down to what feels like 40-50FPS when its exported. Any ideas on why this is happening and is there anything I can do to fix this? I attached the gif that has the wrong FPS, I don't know if it will help but at least it will give you a visual.