Section of LED christmas lights are dim

I have a 60ft string of white LED Christmas lights and a small section of the lights are dimmer than the others. Approximately 30ft are good and bright then about 10ft are dim and then the other 20ft are good again.

All the bulbs are working and are very consistent in brightness including the ones that are dimmer.

Any ideas on fixing them, would like to fix instead of replacing the whole thing.

Thank you