Why is the Gmail font getting smaller on it's own?

[iMore Question]

The font is already too small, but then for some reason will shrink in size. There are times when I can't attribute it to any action I've taken, but theses almost always cause the problem;
- inserting a link ( a copy/ paste )
- copy and paste anything, regardless of the text size that was copied, it seems it's always smaller when pasted in Gmail. Then, my message font continues with a smaller size!?
- INSERTING ANY EMOTICON, or any item from the keyboards emoticon library! Afterward, my message font size is reduced!??

What's going on here?

 

[Just_Me_D]

Re: Gmail font gets smaller on it's own?

How are you accessing your Gmail? Web page, Gmail app, 3rd-party app? Have you sought assistance via Google support regarding this matter?