Frame expansion question

Hey guys, i have small doubt here you see:

I want to animate the traditional way, and as some of you may know, i have to set up my keys first, however i’m noticing that whenever i draw a new frame, the previous one expands, i don’t know if this is normal or i did something which i cannot fix XD ??

*Image attached so you can see what im talking about

**And what does the little red pencil on the xsheet means ??, 'cuz it shows up a lot, and i’m sure it has something to do with this


In Harmony Preferences / Exposure Sheet / uncheck “Extend Exposure of Previous Drawing”.

It shows that you have modified a drawing, but didn’t saved it yet.