I've found - when using ChatGPT with GPT4 - that sometimes when I ask it to do two things like that it will ignore my request to do one before the other and try to do both at the same time before providing a combined answer, unless I give even more specific instructions along the lines of "do not <do whatever> until after you have entirely finished and answered to completion <first thing>".

Just FYI in case anyone reading your comment tries your suggestion and has same issue, that with more firm instructions the problem can be avoided. Though I've not felt the need to experiment enough to understand exactly where the line is to avoid it trying to start one task too early without being wastefully verbose in the prompt.