Map markers are not updated when photos are moved in the map module

Just starting today the Map module is leaving behind markers for a photo or photos that have been moved. It also continues to show markers for photos that have been opened but are no longer in the directory being worked in. If I leave LRC and come back in, all is well but I've never had to do this before. It is more of an annoyance than a major issue, but it does clutter up my screen while moving things. I am in the process of locating old photos that have inaccurate or no geotagging and this behavior is slowing me down. I’m running 15.3 on a MacBook Air. Has anyone else seen this or have a suggestion of how to fix this behavior?