For Xfce there is a new report: bug 1737320
Changing "self.set_resizable(False)" in /usr/lib/python3/dist-packages/UpdateManager/UpdateManager.py should allow you to resize the window.
For Xfce there is a new report: bug 1737320
Changing "self.set_ resizable( False)" in /usr/lib/ python3/ dist-packages/ UpdateManager/ UpdateManager. py should allow you to resize the window.