This scenario usually happens during heavy rainfall.
Gutter nails loose.
If you have u shaped brackets holding your gutter from underneath change out the ones that are broken or loose.
Gutter nails secure the gutter to the side of the roof or the fascia.
You should really consider using gutter hangers with screws or if the screws are not long and or thick enough since you re likely going in an existing hole get hangers without the screws and use your own screws.
If your gutters use long spikes or nails that go through the front of the gutter replace them with threaded spikes for a more secure fit.
However these fasteners can come loose from their respective locations and cause the gutters to hang away from the roof.
You may have to temporarily remove your hangers as you go or you can notch out the apron around them.
The advantage of screws vs nails is that screws are much stronger because of the threads and are much better at not allowing the gutter to move as much depending on the weather.
Gutter spikes are often referred to as gutter nails or gutter screws but they are all basically the same thing.
Replacing them with steel gutter screws and rigid plastic ferrules provides a more secure alternative and will prevent them from pulling loose or sagging.
To replace gutter spikes with screws simply remove the old gutter spike and insert the screw through the existing hole in the front of the gutter.
A big nail that goes through the gutter and mounts into the rafters of the fascia board.
This causes water to leak into the exterior walls of the home.