WP Super Cache has been running wonderfully for us for a couple of years.
However, today we noticed that expired cache files were not being cleaned up. Manually deleting the cache has certainly helped, but in troubleshooting, I've run into something weird:
On the Advanced tab, I have:
Cache Timeout = 1800 seconds
Scheduler = Timer: 600 seconds
However, when I go to the Contents tab, I see:
Last GC was 14:22 minutes ago
Next GC in 55:38 minutes
With the scheduler set to 600 seconds, why would the "Next GC" ever show a time longer than 10 minutes?