Is this in the latest version? I did fix a similar bug in 13.5.
I've been trying to get it to handle monitors with custom scaling (i.e. in your system display settings, each monitor has a scale option) but it's a bit tricky since i can only test with what I've got. I have been testing it with different monitor scales but mine only go up to 175%.
You don't need to reinstall to fix it, if you delete config.xml it will get recreated with the default values, including window size.