As @ScottShearer and I both suggest, you need to rethink your Flow design. I don't personally see how this design will function well if at all.
A delay delays the entire Flow branch it is in. You're using a delay within the "Do until loop," so until that loop step is completed no other parts of the Flow will run, unless you have parallel branches.
If you could provide an expanded screenshot of your Flow and steps, and of any detailed error messages you're receiving we could likely better assist you.
If this reply has answered your question or solved your issue, please mark this question as answered. Answered questions helps users in the future who may have the same issue or question quickly find a resolution via search. If you liked my response, please consider giving it a thumbs up. THANKS!