When using the slow motion mode my FPS drops from ~500 to 60. When looking at the console its returning the same error over and over again:

DispatchAsyncEvent backlog, failed to dispatch all this frame. 163 of 4562 remaining
DispatchAsyncEvent backlog, failed to dispatch all this frame. 102 of 255 remaining
DispatchAsyncEvent backlog, failed to dispatch all this frame. 170 of 4562 remaining
DispatchAsyncEvent backlog, failed to dispatch all this frame. 60 of 255 remaining
DispatchAsyncEvent backlog, failed to dispatch all this frame. 146 of 255 remaining
......

This error is known to cause FPS drops but to this date it's still unclear what causes this error. Since it gets triggered when enabling the slow-mo mode, maybe the cause of the error can be discovered.