A walk on the roof might be quite enlightening.
ANY gaps or deep cracks in the DICOR sealant must be fixed.
If the leak is below the air conditioner, the foam seal could be the culprit.
An improperly torqued foam seal can leak over time and once there is a "path" between the seal and the roof, it will always leak in the rain from then on. Replacing the seal is your only option for a permanent repair.
The yellow torque tabs should "just" kiss the roof material at all 4 places for a proper installation. If they are tightened past that, the foam seal will not make even contact with the roof.
Lou, Laura, & Freya the wonder dog
2008 GMC Sierra 3000HD Crewcab SB Allison Duramax
2019 Flagstaff 8529FLS - Pullrite 3300
HAM CALLSIGN - KC3FFW