Buick Enclave Owner's Manual page 60

Keys, Doors, and Windows 59
If frost or other conditions prevent
closing, override the feature by
closing the sunroof in manual mode.
To stop movement, release the
switch.
Dirt and debris may collect on the
sunroof seal or in the track. This
could cause an issue with sunroof
operation or noise. It could also plug
the water drainage system.
Periodically open the sunroof and
remove any obstacles or loose
debris. Wipe the sunroof seal and
roof sealing area using a clean
cloth, mild soap, and water. Do not
remove grease from the sunroof.
If water is seen dripping into the
water drainage system, this is
normal.