I submitted a buyer's agent showing request that was accepted. The agent accepted it by mistake and canceled. Will my request go out again -OR- do I need to submit a new request?

If the cancellation was outside of the two-hour window of the showing time, it will automatically repost. If the seller canceled the showing then it will not re-post.

Canceled showings within a two-hour window of the showing will need to be submitted as a new request. Showings within an hour of the showing cannot be submitted because one hour’s notice is the minimum time allowed for showing submission.