Display defaulting to 29hz interlaced when switching resolution to 1920x1080

Hello, I am having an issue with my newly purchased AMD R7-360.  This is my first AMD card after several Nvidia GPUs and I am having the following problem.


A little background:  I have a Samsung KU6300 40" 4K TV I use as a main monitor.  This TV supports 4k @ 60hz, and I previously was using an NVidia GTX 1060 which supported HDMI 2.0 and had no issues using the display at 4k @ 60hz in desktop on Windows 10 Pro.


Problem I'm having:  With the AMD R7-360, when i switch resolutions to 1920x1080 (doesn't matter if I switch from 3840x2160 or 1600x900 for example) the refresh rate always goes back to 29hz interlaced.  I can go into my settings and change my refresh rate to 60hz and it will take and run fine.  This is an annoyance because I keep my desktop display at 3840x2160 @ 30hz but playing games will cause the fps to cap at 29 because of this.


I am aware that the R7-360 only supports HDMI 1.4 and I should expect only 30hz at 3840x2160.  The fact that the refresh rate always is defaulting to 29hz is causing a headache.  If I set up a game for example to render at 1600x900 the refresh rate will set to 60hz.  I don't know if there is something weird going on since 1920x1080 is 1/4 of 3840x2160?  If I change my desktop resolution from 3840x2160 to say, 1600x900, my tv goes black for a few seconds then comes up in the new resolution with 60hz refresh, but I've noticed if I go from 3840x2160 to 1920x1080 the screen immediately changes and does not go black for a few seconds.


I have the latest drivers installed (17.7.2, minimal setup, no ReLive) and Windows is fully up to date and it's a fresh install, no previous GPU drivers.  Any ideas on something to try?  Thanks.