QLibrary::resolve documentation states following:
"Loads the library fileName and returns the address of the exported symbol symbol. Note that fileName should not include the platform-specific file suffix"
In src/plugins/bearer/nativewifi/main.cpp wlanapi.dll is passed with suffix. This causes the process trying to first load wlanapi.dll.dll.
I think this could be fixed there (in wlanapi.dll) or even better make change in QLibrary and update it's documentation related. See my patch attached.