This problem could have caused more issues had it not been addressed. The wood sheathing had major water rot. After removing the section of shingles, we cut out the bad wood, replaced it with good. then installed underlayment and finally the shingles.
Shingles were cracked and falling apart in the section of the roof. the vents were not properly sealed, and the boots on the vents were cracked and leaking water. We fixed it!