Font size

So, why can’t i change my font size or image size? The tool is there on the left side of the text window, so I press the button and scroll up. I increase the font to the size I want. Then I go to the next text window to adjust it, and the other window pops back to what it was before. Same with changing the size of the image. Why does it let me adjust it, and then it just pops back to its original size?