This has been going on since new.
When the wipers are on and set to a delayed setting they work fine except about every 4th or 5th wipe the wipers will go 3 times in a row, then back to their delay setting. This repeats as long as the wipers are set to delay. On low or high they work fine.
This is our 1st MH and not sure if it's normal in my 2007 Southwind, F53 Ford.