SOILGRIDS: Timeout error when linking layer as WMS in QGIS

I have added clay content as a WMS layer in the database manager of QGIS 3.14. I consistently get the following error:

2020-08-29T10:32:40     WARNING    Network request https://dev-maps.isric.org/mapserv?map=/map/clay.map&version=1.3.0&service=WMS&request=GetLegendGraphic&sld_version=1.1.0&layer=clay_0-5cm_mean&format=image/png&STYLE=default&TRANSPARENT=true timed out
2020-08-29T10:32:40     WARNING    Network request https://dev-maps.isric.org/mapserv?map=/map/clay.map&SERVICE=WMS&VERSION=1.3.0&REQUEST=GetMap&BBOX=-55.97729999999999961,-179.9979999999999905,82.71930000000000405,179.9939999999999998&CRS=EPSG:4326&WIDTH=1204&HEIGHT=465&LAYERS=clay_0-5cm_mean&STYLES=&FORMAT=image/png&DPI=96&MAP_RESOLUTION=96&FORMAT_OPTIONS=dpi:96&TRANSPARENT=TRUE timed out

My own internet connection fast and stable, I don’t think it is on my end. I can download tiles from https://files.isric.org/soilgrids/latest/data/clay/
but then I cannot find how the tiles are coded (I need a part of Haiti).

My students do not know python or R (yet) so I prefer the QGIS method if possible.