When changing the size of the text in a comment box, after you adjust the size and click save, then close the material editor. When you reopen the editor, the text size is back to the default but the newly adjusted text size is still indicated in the details panel.
I was able to reproduce in both 4.25.3 and 4.24.3
1) Open the editor
2) Create new material
3) Create new comment inside the material editor
4) Change the font size of the text of the comment (for example 50)
5) Save and close material
6) Reopen material
The text reverts back to its default but the font-size says the adjusted size.
The font-size changes when you reopen the editor.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-97445 in the post.