Glad you figured it out....BTW, the same thing will happens to windows with a rubber seal (especially emergency exit windows that compress with a lever ask me how I know....
).
For a product to try that will eliminate seizing - Spray Silicone wont harm rubber or aluminum, it's water repellent, and it sure wont stick. Use it sparingly (spray into a cloth and wipe on / wipe off) or you could attract dirt.