Side won't advance automatically even though set to

Both advance automatically after X seconds and after click are set. I am using timings. I want it to advance after a pre-rehearsed timing, and it will not do so. It also will not advance after X seconds. It will eventually advance about a minute late. It doesn't matter what I set the "advance after X seconds" to. There is always a long delay before it will auto advance.

The sound was re-compressed with a different program to make it smaller and then imported back in, but that hasn't caused an issue with the other slides.