I write my posts directly in ActiveRain (not imported) then format just before publishing.  

Another option that should work is to import your content then highlight all the text and clear the formatting (as shown below). Then you can reformat to your liking.

Strip your HTML like Carol Williams said. You cannot do a few features like change your font colors or font sizes like before. System updates want posts to all look cohesive.

I write my posts here rather than copy, pasting. Before posting, select all the type at once and then click on font size you want and then post. It corrects the size problem.

I write in Word, copy and paste into the editor, then clear the formatting as Carol has shown by highlighting and clicking the T icon. Then I  bold, italicize, etc. to my heart's content. Some shorter posts I just write directly in the editor.

Must admit that Brian England has a good suggestion while I have no clue! Good luck.

It works better if you write your posts directly into the AR editor, then the formatting doesn't mess up.  But like others say - click on the clear formatting.

I think the html code gets messed up.  That used to happen to me and I got a tip to copy the html code from a post that was properly formatted then paste it into the html code section for a new post and then edit the new post from there.

This visited with me as well...Lets get some answers

Sounds like there are others who have had the same issue and now we have the answer!  Thanks for asking as I've also had this happen to me. And now I know what to do about it.

Carol Williams has this one ... you must clear formatting. 

Well now I know what to do should this happen to me thanks to Carol Williams !

If you write it in Word or another third-party processor first, it won't import properly.  You need to write it in AR.  Or at least copy it from your processor and paste it as clear text (usually Ctrl+Shift+V) and then apply the formatting you want.  AR also has a limit (or will) as to which fonts can be used as they move to a more unified look and feel.

By the time I got here you had received the answers to your question

Use the Tx button on your toolbar to clear the hidden formatting then format it the way you want it.

copy and paste doesn't work unless you strip the code out.