Switching from Phone to Computer

I used to sign on to a meeting on my phone and the app on my computer would offer to allow me to switch to the computer from the phone.  Recently, that option has stopped. I looked up a fix online and the information I found should have helped but the option it suggests doesn't show up for me in account settings.

Any help with this is appreciated.  Also, the app switched my avatar pic to an old one... just did it on its own.  What's with that?