A separating gutter deserves assessment of its attachment and the supporting fascia. Refastening into deteriorated material may not address the underlying condition. The surrounding roof edge can also need review.
What to do next
Ask for photographs showing the support and affected area. Have the proposal distinguish gutter work from fascia or other repairs. Keep responsibility for each component clear so the finished gutter is not attached to an unresolved substrate problem.
Related Perkins guidance
Contact Perkins Roofing to discuss your roof and the appropriate next step.