The answer to 'roof vent curling' is that it is a common issue caused by exposure to UV rays, temperature changes, and aging materials. Symptoms include the vent flashing or collar becoming warped, cracked, or pulling away from the roof. Solutions can range from resealing or replacing the vent to completely replacing the vent and surrounding roof area.
If the curling is minor and the vent is still functioning properly, you may be able to DIY the repair by resealing the vent with a roof sealant. However, for more significant damage or if you're unsure of the root cause, it's best to call a professional roofing contractor to inspect and make the necessary repairs. They can properly identify the issue and use the right materials and techniques to fix the problem and prevent further damage.