‎I have also had problems with these loops. Often times I cannot simply delete the loop because it has house numbers associated and I don't wish to manually re-enter all of these. And besides sometime I try to delete and WME throws an error when saving.   Using the WME toolbox it often shows a dead end marker as well. The advice given is to split the loop into three pieces. I have tried this as well and still no luck.  

What I finally learned to do is to select the node connecting the loop to the road. Make sure only the node is selected.   Then disable all turns and re-enable all t‎urns. What ever this releases makes all the former advice functional.  

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WME Link

Delete the entire loop and do it as two separate roads. I.e. one half way, then the other from there to the original connection.