Typing in Yahoo Mail
 

I’ve got his rather weird and frustrating problem when typing in Yahoo Mail that I could really use some help with to eliminate. Sometimes, when auto correct indicates a spelling error and I click on it to correct, the whole chapter will suddenly change to a different font size, usually “Tiny.” This also occurs when I do a manual spelling correct. Does anyone have an idea how I can prevent these unwanted font size changes? Many thanks.

I'm assuming that you're using their web based mail client so it may be worth trying a different browser? Have you consider using a different mail client to access your email such as the Mail client built into your Windows or Mac OS or even Outlook?

If you are using the web based client, then the best solution would be to contact the Yahoo help desk. It may be a quirk in their programming and nothing to do with your system. Then again, it may be some other browser extension getting in the way, there's not a lot to go on. As Specaircrew mentioned, changing the browser might help, disabling add-ons and extensions within the browser could be an option (temporarily, just to find out if one of them is the culprit), you could try a 'private' window to see if that makes a difference.

Any browser weirdness - worth clearing the browser cache.