The top number is taxable per diem. There was an issue with the IOCC cutover that caused any modified trip to be broken in day trips, i.e. your middle SAN turn canceled but you still went to your overnight, you now worked 3 day trips instead of one 3-day trip.
So you probably got shorted per diem and screwed with taxes. You can still write it off from a tax stand point though if you itemize.
WRT to aTomatoFlames, anytime you’re away from domicile for a night (more than 50 Miles) it automatically becomes tax deductible. If you do any overnight it’s non tax per diem. The state doesn’t matter.