Recently when I open a file and want to edit some texts, them have a weird behaviour and seems that some properties change (letter spacing, line height). I’ve attached a video with the problem.
Where did the file originally come from? If you pulled it from somewhere else and the original file includes fonts that you don’t have on your computer (or isn’t in the Figma library), then Figma will treat the text like an image, until you go to edit it. Then, I think it converts it to a text that you can use. In the top right corner, there should be an exclamation mark indicating that the file has unrecognized fonts/typefaces.