I have written a Qt application for displaying and modifying GPS location data in photos.
Maybe it is interesting for some of you. See http://www.tvdr.de/geotagger.
It’s FOSS, so maybe openSUSE would like to consider adding it to a future version.
Sorry if this is not the right place to suggest an application, I didn’t find a better one.
I get the same messages when using OSM as map provider (normally I use googlemaps, see “GOOGLE MAPS PLUGIN” in the README file).
My version of Qt is also 5.15.2, the only difference I see is that you’re using the version that comes with Tumbleweed, while I use the one downloaded from qt.io (plus I am running Leap 15.3, but I don’t think that should make a difference). Would you mind trying to download Qt directly from qt.io, just so we can rule that out? You can install it into a local directory (as a normal user) and just call the qmake from there. Later you can simply remove the whole Qt directory and it won’t leave a trace.
Note that GeoTagger can’t be built with Qt 6, because it lacks the “positioning” and “location” modules.