When I added the new location to my site with address as Place Verte 21, Spa Belgium postal code 4900, google came back with a different LAT/Long then what you are showing.
So I then just went direct to Google Maps , not usingSLP plug in and added address Place Verte 21, SPA belgium and got the same results
the lat long as shown here https://www.google.com/maps/dir/Place+Verte+21,+4900+Spa,+Belgiumfirstname.lastname@example.org,5.8589588
When I add your Latitude and Longtitude using any browser it comes back as the Hotel r…your Lat and longtitude is incorrect
I dont know what changed but your import of that lat and long is not correct according to Google (I even tried using Bing Maps) since the plugin is based on Google Maps , you need to correct the lat and long.
Try that and let me know how it works for you.
P.S is there a reason you haven’t updated your WP Plugins? The error messages I are many.