Bizarre routing away from roundabout then back to it

Any thoughts on what may have caused this bizarre routing? Waze suggested route took user off the A421 to the next roundabout north, only to then immediately go back down to the previous roundabout and continue on the journey!!

Edit - and potentially another one in a different location, as the Waze suggested route takes the same approach of lets go off the logical route for one roundabout and then back again!!

https://www.waze.com/forum/viewtopic.php?t=354567 Somethings not been right since the tile update delay a few weeks ago. Also issues with navigating to Google places again.

And another occurrence!