Placed a few bets recently on the horse racing markets most recently the 3.05 at Ascot.
The bet appears in the box for roughly 5 seconds then disappears showing the next best available price then reappears again 5 seconds later. The annoying thing is the lower price gets taken while my bet gets missed. FWIW I was offering the better price there for should be getting matched first. Have noticed this happen a few times recently.