When you're on a two-way call and put someone on hold, they can unmute themselves and you'll be able to hear them. This becomes a problem because while you're on the other call, you can still hear the person who is supposed to be on hold.
Workaround: There is currently no known workaround for this issue. If you have experienced this, please reach out to support. https://fyihelp.zendesk.com/hc/en-us/requests/new
Devices Affected: IOS & Android