Issue:
By default, all text gets added at a size appropriate to the drawing’s current zoom level. However, when you want to export your work, the various text sizes may not be ideal for a final presentation.
There are two ways to “fix” this issue.
Solution #1
Set the text size to never change. Under the Annotate Tool, select "Colors an Styles" to adjust how all the text will appear on the drawing.
Solution #2
Once you are ready to send out / show your work – change all at once.
The video below shows how to select all text and make them all a single appropriate size.