iMovie iOS clips missing last few frames

When splicing together video clips, the last few frames of a clip are not preserved. Duplication steps: 1) record two videos using the default Camera app; 2) splice together these two clips in iMovie, export (no fade out or anything after the last clip); 3) splice together these two clips in the third-party app Splice (by Bending Spoons), export (ditto); 4) compare the last few frames of the iMovie export with the last few frames of the second clip used and of the Splice export; notice the iMovie export is missing those frames unlike the other two videos. Dragging the end of the clip in iMovie doesn't work to return these frames. Perhaps other frames are missing too but haven't tested. iMovie for iOS 13.3. Reported bug to Apple. Meanwhile, is there a workaround to recover these frames when using iMovie to splice?