It appears that when Bob imported our profiles, any links in the signature were changed from HTTPS to HTTP. Now that Bob has a certificate installed, this breaks your signature. The fix is easy…
Go to the top right of the screen and click on your profile picture.
Then click on the Person icon at far right of the pop-out box.
Then click on Preferences, the far right selection in the account options.
Then click on Profile at the left to open your Profile Preferences.
Near the bottom of the page find My Signature.
Look through the text in the edit box and be sure any photo links are set up as HTTPS:\ not HTTP:\
Click on Save Changes at the very bottom.
Your signature should now show up correctly.