Just noticed there was a thread dedicated to infinite scroll, so I'll continue the report here instead.

Apostrophes are being rendered into multiple spaces, and it seems to occur more frequently with specific users. It occurs on macOS and Chrome, but not Windows and Chrome. On Firefox, the apostrophes are deleted completely (e.g. That's --> Thats).

To recreate the issue:
https://www.flyertalk.com/forum/31352812-post6.html

Examples:
https://www.flyertalk.com/forum/31748113-post1596.html
https://www.flyertalk.com/forum/31519253-post1519.html
https://www.flyertalk.com/forum/31600328-post1536.html
https://www.flyertalk.com/forum/31604715-post1544.html