Closed Wargroove 1 S-Ranks Not Triggering

I've been playing through Wargroove on mac and just about everything has gone smoothly thus far! Until now, the only bug I saw was Emeric's Cherrystone not being labelled properly in a unit damage info menu. Now however, I'm going back through the main campaign and trying to S-rank every level, except that I'm not always getting S-ranks when I should be.

The attached screenshot is the best example of this. For Act 2 Side Mission 1, Canine Justice, the overview menu says that the stage needs to be won in 16 turns to receive an S-rank. I won it in 13 turns, but got an A-rank instead. I also had this issue with Act 2 Side Mission 2.

I've been able to get S-ranks on several main missions and some side missions already, but I can't confidently continue when I could be pouring time into missions only for this bug to discount my efforts. Please fix this issue.

 

Nevermind, didn't know that using checkpoints voided S-ranks