Semi-Monthly scheduled transaction is constantly deleting 1 of the two instances (Q Mac)

I have a semi-monthly paycheck that's been scheduled for several years and just in the last 60 days or so it is deleting 1 of those monthly instances every time I update my accounts. So my paycheck on the 15th and end of month ends up only showing up on the 15th and not the 30th/31st. I have to reset it every time. I can reset it no problem, and I can even do two separate monthly instances instead, but that seems weird and it's never had this problem before. Very strange.