multiple email accounts broken from button

i have multiple email accounts in outlook and could choose which email address to send from but now for some reason i can only send from the default account  even though the from shows up when you click new email the from button is there with the down arrow but it does nothing and is not clickable.

Have tried  totally uninstalling  and reinstalling outlook from fresh install but still have the same problem I have used the same pst files for the email accounts  could this be the problem tried the outlook repair program  but nothing works apart from going to account settings and change the default account