Fiverr only allows 10 sellers from each level to make offers on buyer requests. Because so many sellers who are level 0 or level 1 depend on BR to get jobs, there are naturally more of those level sellers making offers to each BR.
Therefore, when 10 sellers like you, who are level 0, apply for a job Fiver pulls that BR from view. So, if you were typing up your offer the BR could disappear in the middle of your typing. I had this happen to me many times when I first started out. It was frustrating! :face_with_symbols_over_mouth:
Once you get to level 1 things, get better. Answer copied from @vickiespencer.