Are you maybe using the window's size for some position calculations?
For example, something like:
// get window centre
sf::Vector2f windowCenter{ rw.getSize() / 2.f };
or to calculate the sizes of tiles etc..
Instead, consider using the size of the view (presuming that the view's centre is its size/2) to make these calculations. Something like:
// get window centre
sf::Vector2f windowCenter{ view.getSize() / 2.f };
You can also get the window's current view and either 'watch' them using a debugger or output the values somewhere. You should note the size
and the centre.
sf::View viewForDebug{ rw.getView(); };
sf::Vector2f viewForDebugSize{ viewForDebug.getSize(); };
sf::Vector2f viewForDebugCenter{ viewForDebug.getCenter(); };
std::clog << "View size: " << viewForDebugSize.x << "x" << viewForDebugSize.y << "\n";
std::clog << "View centre: (" << viewForDebugCenter.x << ", " << viewForDebugCenter.y << "\n";
Track it as much as possible and at different points. First place would be at the point of drawing where it is not what you expect.
Then, once you know the view is what you expect - size: 1920x1080, center: (960, 540) - you can be certain that it's not being used correctly elsewhere.
Also, note that if you're using multiple views, 'getting the view' will only get the currently set one.