When you have long file mov names the timecode numbers get pushed to the bottom right of the playhead timeline slide. This makes it hard to see and grab the right trim handle. The only solution is to temporarily resize the Src window to expand the height of the slider to expose the trim handle. Only an issue when using high res displays, 4k etc.
One solution could be to add some padding at the bottom of the slider so that the timecode numbers don’t obscure the trim handle. Or steal some pixels from the rate slider.