I imagine there are many factors involved, and the possible solution(s) will depend on which ones are actually happening. While you've provided some details on when you see the issue, it would help immensely if you could tell us more:
Are you seeing the issue when previewing on PD's timeline, in the finished (produced) video, or both?
If it's present in the produced video, are you seeing it on a Windows player (Windows Media Player, VLC, Movies & TV) or online (YouTube, IG, FB) or both?
Does it matter how long the first clip is before the cut or transition? In other words, does the issue happen with a 1 second clip or does it need to be 10 seconds or longer to occur?
Do you have any CLUTS or presets applied to any involved clips? Any editing changes to brightness/contrast/saturation, etc.?
Are any of the clips overlaid (like picture-in-picture)? Are any titles used immediately before, during, or immediately after the cut or transition?
It would also help to see a screen recording showing us exactly what you see. You can post it online and share a link or upload it to a cloud folder on Google Drive or OneDrive and paste a shareable link to it here.