I thought me jill was playing up too. but when I find she does this she's got a rabbit in a stop end and cant shift it, so she comes to the entrance hole then quickly back down (when I reach for her). 
  
took me a while to cop this on, but the rabbit sometimes bolts when she leaves or I get a mark on the locator for a dig when she returns. try it next time your out,  worked for me.