Sam I don't use Outlook so I don't know how to fix your problem but I'm wondering if Outlook has a conflict with your set chrome browser font size, not being the same size as theirs and I really don't know a "For Sure" solution but why don't you try changing your browser Font size so it's bigger or smaller to see if that helps.

Click onto the 3 dots on the upper right side of your browser, scroll down to Settings and click onto that and then in the left side menu choose Appearance, scroll down to font size, click onto customize and move the blue lines right for larger, left for smaller till you find the size you want. You'll see the sentence on that page "The quick brown fox jumps over the lazy dog" become larger or smaller, so you can judge the font sizes that way. It's really the minimize font size that you want to make sure that is large enough for you because that's the one that some pages default to.

Before changing the sizes, mouse over both "Font Size" and "Minimum Font size" to see what size they are set at before changing, that way you'll know what to change them back to if changing them causes you more problems.