iTunes songs running into each other

I've been having this issue with my music since I got a new computer last Christmas. My songs run into each other or cut off and jump to the next one prematurely.

Ex: A song is playing but ends at 50 seconds and goes into the next song. It still reads as Song A playing but Song B is playing. If I jump to the next track, it just picks up wherever it was.

Some songs play just fine in iTunes but are problematic on my phone and iPad, others happen on the devices and in iTunes on my computer.

I've searched for help, I've deleted music and re-transferred between computers and devices, nothing fixes it. The files shouldn't be corrupted. I don't know what the problem is 4+ months later, I need it fixed. :(