Yes, I see that you have converted the original video file (from a mobile phone with a variable frame rate) to a user-friendly video file (UtVideo).
But you do not have preview scaling and proxy function enabled.
To improve preview performance (because this seems to be the problem) you can enable preview scaling and proxying.
I link relevant technical information as well as a practical video about these functions.
I hope that with this, the performance will be better.
Tell us about it.