Indesign - Font types and sizes are jumping around

Sometimes when changing the size in the toolbar, when pulling the mouse away from the size field, Indesign jumps the font and/or size to something else entirely. So let's say I'm working with Euclid Regular at 8, and want 9.75... after typing in 9.75, I pull the mouse from that area and next thing I know, the font is something else entirely (not the same font ever) and another size (like 4pts). No, there's NO parenthesis next to anything. 

What's the deal? Is this an auto feature? it's maddening. 
I'm rated Top 5% of Indesign users and have never seen this before the last year or so.