Delay when updating an email

I've been having a few issues in the design studio lately and this is one that I really don't understand.

I will update the subject line of an email, approve the email, then send it using a single flow action.  The email I receive will have the original subject line and not the new approved subject line.

I was eventually able to send the email with the correct subject line, but not until after I logged out of the system then back in.

Is there a delay time for updates I should be aware of?