If I've looked at the correct listing then that bidder has over 120 bid retractions in the last 6 months - add their id immediately to your blocked bidder list and report here:-
Follow up the report with a poe call to eBay customer support tomorrow morning and ask them to review the bidder's retraction history which seems excessive (being polite here) and you suspect auction interference (bidding to expose the high bid). State that you have added the bidder's id to your blocked bidder list as their bid activity was unwelcome.
