wrote:
This should be covered under warrantee. Are there attic ventilation or
decking issues that contributed to the failure? Will the repair fail
prematurely for the same reason?

Shingle warranties are prorated and a total joke. The manufacturer
always comes up with an unproveable excuse as to why they will not
honor the warranty... improper installation is their favorite. They
always end up telling you to go **** up a flagpole.