Updated my S9+ to the stable Android 10 this morning and later when I tried to connect to my screen to use in Dex mode, absolutely nothing! Did Samsung disable Dex on older phones or support for non-Dex accessories?! This is really disappointing. Unable to find it in Settings too.
All settings are as is. Haven't changed anything. Normally, it detects HDMI connection on it's own and Dex loads. Would get an on-screen pop-up for HDMI, which also isn't showing up.