Hello ScrewLuix, thank you for posting and welcome to the Unreal community.
Your concern has a few solutions. One is exporting from Unreal Engine then reimporting them. Another is changing the frame import range.
There is an interesting thread that sounds similar to your concern.
The replies below also state that exporting and reimporting the animations will help as they have found Unreal Engine exports at a set FPS.
In another thread, it is explained that the frame import range may need to be adjusted.
There is a lot of information presented but I hope this helps.