need your opinion

I inspected a single family home, built in 1988 in TN.
I could only walk part of the roof before the heavy rain started, but I noticed that several shingles were replaced and some had weird damages.
The drip edge and other roof flashings have been wrong installed and there were several moisture problems inside.
The roof ventilation is mainly thru the gable end, and I could only access part of the attic over the garage, not the main structure. The damages are present throughout a few hundred square feet of shingles.
I noted this in my report.

What do you think might be actually the reason for the damage of the shingles.
There is also one active roof leak present, but I couldn’t determine the source.

Hard to tell what caused the damage. Overhanging branches, storms, foot traffic???
I would report: The roof has been patched, granule loss is visible and there is a current leak. Roof should be assessed by a licensed roofing contractor and repaired as needed.

Not my job to say what has caused the damage I try to never box my self in case of saying the wrong thing it can come back to haunt you .

Roof has been damaged and repaired .

Recommend having it checked by a Roofing contractor immediately and have it repaired or replaced .

Which planes exhibited the most damage. When I see that kind of pitting here, the attic is usually inadequately vented and the damage will be most severe at the west and south facing planes. That kind of pitting can be caused by blistering of the shingles, which can be caused by high heat.

Anytime you see spot replacement of shingles check carefully for damage to the surrounding shingles and broken bonds that were not hand-tabbed. Good job on the photos BTW.

What Chuck said - blistering, likely caused by inadequate ventilation.

I would add that the shingles are showing deterioration consistent with age and/or manufacturing defects.

On your report, I would suggest as others have; report the damage observed and recommend evaluation by a qualified roofing professional. If you attempt to diagnose the cause, the seller might seize on that as a point of contention, hoping to undermine your observations as a whole.

That said, it is good to learn what could cause this kind of damage. A puzzled shrug does not engender confidence amongst your clients.