With Ocean City's climate - mild with occasional freeze - the metal itself isn't the main culprit the way it would be somewhere with real freeze-thaw cycling. Here, it's usually mechanical: a roller bearing worn out after close to fifty years of cycling, or a bracket that's slowly worked loose from repeated door slams.
The tell is usually a door that runs crooked before it fully derails. One side drags, there's a scraping sound low on the track, or the door looks slightly cocked in the opening when it's halfway up. If you catch it at that stage, it's a lighter fix than waiting until the door comes fully off the rail and jams in the opening.
A fully off-track door that's stuck partway is also a door you shouldn't force by hand or with the opener. Leave it where it stopped and call. Forcing it usually bends the track further or pulls the bracket the rest of the way loose, turning a one-section repair into a full track job.