There was a new option added in MainMenu>Settings>Advanced>Web Page Display called Page Font Size. The default is "Medium but theree's a problem with recognition of this setting initially, so pages display ultra-tiny (fonts and images).
You can correct it by changing "Medium" from that to another setting and back to Medium. Easier is to click "Set to Default" button. I think this is good for a Mx5 session, but may need repeating each time you launch until a fix is made - inconvenient to be sure.