Its not a industry wide issue but may be with Jayco Jayflight models. I would send them the pics and see if they have a opinion on the issue.
What causes this ?? The moulding needs to be removed and a determination if the front wall/sidewall has detached. Sometimes the trailer can be twisted from off road use or wrong jacking methods and corner separations can be the result.
Self help ? All depends on your fixing structure skills and ability to find what caused the issue. Hand tools and a structure to keep it rain free while you do the R&R.
Danger ? Only if the corner has separated and let water inside. The roof is still holding front wall/sidewall. How does the roof/front wall joint look up top.
Good luck and keep us update on what going on with this issue.