Qt Location Open Street Map Plugin: tile request error "Problem with tile image"

I use the Qt Location Open Street Map Plugin with QML Maps almost daily.

Since yesterday the OSM plugin is showing an empty (gray) map, and is throwing the following error on the console: 

tile request error "Problem with tile image"

This issue can be easily reproduced by running the Minimal Map (QML) example from the Qt Documentation.

I have attached a screenshot showing the output after running the Minimal Map example: an empty map.