Outlook - Office 365 has changed formatting

[1Begonia]

Overnight my Outlook has changed the formatting to my email. I'm calling it formatting - not sure if that's the correct term. My "reply" and "compose" have the new paragraph symbol and what appears to be dots/periods between each word. The setting must have changed, but I'm not able to spot the change. I would appreciate help.  

I received this message when posting here - if there was html in my post, I don't know where. 

"Your post has been changed because invalid HTML was found in the message body."

[#2]

Hello @1Begonia I have just joined the Outlook community and posted my first thread.

I was fortunate to invoke PREVIEW for the system to say that invalid HTML had been removed.

invalid HTML removed

I am guessing that previous versions of your Email were saved during compose, but unsure that these continue to be available after posting. Open your thread and look to see if there is a system message at the bottom of your post. If it is not too late, the edit feature in the \/ top-right drop down menu may still be available.

You may wish to visit your settings for Email Format and toggle OFF the default "remove HTML from posts" if inclusion of HTML is intentional. 

Kind regards.