Just want to follow up if it helps anybody. Haven't had this in a while. My earlier method proved to not work sometimes. I've been doing two other things consistently, and so far I've had good luck.
Make sure you press the STD button BEFORE you click the screw hotspot to standarize the backups. It doesn't seem to like the other way around, and causes a glitch in the STD button.
I was flying in the Caribbean so I had the aircraft configured for fuel in pounds but altimeters in hPa. Ever since I forced the aircraft config ini files to be in pounds AND inHG for the altimeter, no problems. Perhaps it was this "mix-match" of imperial and metric units confusing the FMC.