Spikes and ferrules are probably the worst possible way to install gutter especially in the hands of an inexperienced crew. Spikes that don't hit a rafter tail depend on the fascia board only to hold the spike in place. Sometimes they even split the fascia board making it impossible for the spike to be held in place for very long.
Unfortunately with mother nature's forces on the gutter (weight of water in the gutter, wind, ice expanding, etc.) spikes work loose and when several of them loosen, the gutter drops loose from the fascia board where water just pours over onto the roof below or the ground.
This becomes a particular challenge if gutter covers that don't get nailed to the roof are installed on the gutter as they end up flapping in the breeze if the spikes let go.
A far superior installation is to use hidden hangers with screws that screw into the fascia board. Now you have both the swelling of the wood and the turns of the screw holding the gutter to the fascia board.
The good news is that when gutter spikes loosen and the gutter pulls away from the fascia board, it can be repaired. The gutter covers are removed, then all the loose spikes are removed to prevent them from interfering with re installation.
A quality hidden hanger is fastened to the gutter minimally every 30 inches and ideally 24 0r 18 inches apart. The gutter is repositioned in under all the roofing and fastened to the fascia board with the screws in the hidden hanger.
The gutter covers are reinstalled and everything is back to normal.
It's not uncommon to find that spikes have been reset several times into other positions because of past failings. Sometimes the spike gets reset into the bottom of the gutter which will leave an opening for water to escape the gutter and damage the facia. A basic solution for this is to use a small piece of scrap metal and lay it over the hole with Geocel 2030 sealant.