SFB - Black Screen of Death - Screenshare on client side

Our company staff is 100% remote.  Using Macs and PCs.  We do not have Office 365 installed on our company assigned machines.  When our Fortune 500 client books a SFB invite through our calendar, when we click the link we are taken to a browser page and given the option to use the app or SFB.  Important to note is the browser page that opens from the client's meeting invite has a date on the bottom of the page as either 2014 or 2015.  When we enter the meeting and a screen is shared, we see a black box with a toggle in the right corner.  Skype for Business app (which I have setup completely and it the latest version) when used, throws me out of the meeting upon connection and states "meeting has ended".   It is my thinking that our client has a very old server-side install and we are unable to see the shared screen do to this but this is only my initial thinking.  It is completely frustrating that we are unable to see the shared screen for ANY meeting with our client.  Is there any workaround or advise.  Thank you