If you watched the video for even 15 seconds, you’ll have noticed that the HUD (Heads Up Display) aka the mini map down the bottom right, or the objectives in the top right, glitch every now and then. This also happens to be in direct correlation with all of the splitheads I made in the video time line to add in text or other effects. Anyone know what this is a result of? Or if it can be fixed?
It’s hard to get deeper insight without being able step frame-by-frame, but probably that first frame after the split is not seeking accurately. In Export, try turning off “Parallel processing” to see if that helps. Otherwise, first converting the file to something like ProRes or FFV1 might help because it is better suited to editing. Certainly, if your source clip is variable frame rate that will cause a problem. A lot of screen and game capture software records in variable frame rate. Some that let you choose constant frame rate usually default to variable. So, check that. Shotcut still does not yet have a function to check that and warn you. A credible free tool called Media Info can report about variable frame rate. The PotPlayer for Windows integrates Media Info as Ctrl+F1 > File Info tab.
I had a similar issue and your comment helped; I expected that splitting at the playhead would create a new keyframe so that when removing a segment the video would still flow correctly, but this was not not the case. My original video was from screen capture software. exporting as ProRes before editing solved this for me.