FG goes up?

took a gravity reading before cold crashing, 1.022, then after cold crash during kegging 1.024.  What?

Misreading.  Different wort temp.  Could be a number of things.  Close enough to not sweat it.

It was a different temp.  The second reading was way colder, like 40f versus 70f.  How does the temp affect a hydrometer reading?  Didn’t know that.

Density changes with temperature. You probably got a sheet with your hydrometer that had information including a temperature correction table.

Search “hydrometer temperature correction,” you’ll find calculators.  Just have to know if yours is calibrated for 59°F or 68°F (most inexpensive homebrew ones are 59.)
EDIT stupid typo

Got it. Thanks everyone.  That makes more sense. Been doing it wrong this whole time.  That’s what she says.