It is normal that rework is done, which apparently has NOT happened here YET. Only the burr was mechanically removed after welding, and apparently the machine is not very precise.
But that is not a problem. You just have to mention it, and someone will come around and make the edge so that nothing is visible anymore.
Mosquitoes and elephants... mosquitoes and elephants...
P.S. I actually wanted to write something after the first response. But I refrained because I thought someone knowledgeable would come.
Unfortunately, that didn’t happen, so I ended up writing after all.
Have the window fitter come by again and rework the corners. Half an hour of work. Issue resolved.