Teams Desktop App version share only black screen for widescreen. Works on other desktops.

Software Teams: 1.3.00.2879

Windows 

Monitor LG 38wk95c in 3840 x 1600 resolution.

Problem:

When I share my desktop, the other users see a black area.

Background tests:

1) The Browser version of teams  CAN and DOES manage to share the desktop properly, full 5k no problem.    WEB VERSION works fine for wide-screen share.  (Web version has other weaknesses).
2) If the monitor resolution is set to 1920x1080,  classic 2k, then the desktop app share  works.

I have tried experimental mode on and off.  I have cleared every cache possible.  

Reinstalled teams.   Nothing helps.

This is definitely a bug with sharing WIDESCREENS.

When using  2  4k monitors , i can successfully share a desktop.

But if i use a 5k monitor.   Then only black screen appears at the other end. 

It could be a bug in TEAMS on the recipient display process of course.

But why does a 4 k monitor work and 5k not. Especially when the web version can.

This is a major usability issue since you can not quickly share different windows in TEAMS and the web version drops device settings.     

Im losing 20 to 30 mins a day restarting browser, flicking from Web version to App version.

I love the wide screen for everything else.  But teams is a disaster on widescreens.

Very happy to demo to support  team.