Your signature can take up to an hour to update.
If you don't see it on your computer after an hour, it is most likely that your email client has cached it for you - but the recipients of your emails will still get the new updated signature. To test, send an email to a colleague, or your personal email address, and check the email signature as a recipient. You'll see that other people get the updated version.
Your email client will eventually update the signature on your end too, but it may take up to 4 weeks.
If the recipients of your emails receive your old signature - please contact our support for assistance.