Powerpoint makes the font size increase automatically

I have this ppt presentation i was working on, the next day the font size was bigger.

I asked a co-worker to send me his (since it was basically the same ppt, but with some minor changes) and I still could see the texts bigger, I sent him my ppt and he could see it perfectly fine... the same way I save it the day before.

It is the same font, the size is the one changing.