掲示板 Forums - Sentence word marker

So I was using the sentence word marker and then this happened

the marked sentence disappeared but it wasn’t replaced by another, the I picked (I’m not sure). And then all the options disappeared and it looked like this

I clicked get a new words and things went back to normal but yeah idk if this is a glitch or something :/ or just a me problem

Thank you for your response :) yeah I wasn’t sure if this was a bug or not but now I know, that makes more sense