My guess is that one of a couple of different things are happening. One, somone is changing some settings in the options of EW. Or two, and probably more likely,  someone is making changes to the display settings in windows and it's messing up the output in EW, or windows is changing the display settings on its own either by windows updates or graphic driver updates.

Another thing I thought of is if this is a laptop, and you're disconnecting and reconnecting it to your monitors every week, make sure you use the same order to disconnect and reconnect everything. Changing the order of plugging stuff in can affect your monitor output. 

Either way, you shouldn't need to take that time to resize every song in EW. You just need to find the setting that's changing and change it back, or if you're using "Do not autosize text" in EW, you need to set it to "Resize text automatically to fit slide" so it will always fit in the slide no matter what other settings you use.

You can contact the EW support team directly the next time this happens and they can remote into your computer and help you find what could be causing this issue.

Remote Support