Super weird dysfunction in content browser (very slow content reading)

Dear Unreal Engine community!

I downloaded Unreal Engine 4.17 and things looked fine until I decided to checkout free contents available on market. I created a test project, added “Open world collection” content to my test project, then I navigated to the KiteDemo  contents to bring in some of assets used in aforementioned collection.

when I try to drag and drop the desired asset ( or right click), unreal freezes for super long time. for small rocks used in KiteDemo unreal takes about 1 to 5 minutes to finish unfreezing. 
for HillTree_Tall_02  UE goes into thinking mode indefinitely or freezes.

I observed the hardware usage when this state happens, 6% cpu usage, 1026.7 MB Memory usage (constant), 0.1 MB/s Disk usage (constant)
since there is minimum hardware usage, I don’t think UE can communicate with disk drive to read the content, or it’s bottle-necked heavily.

My pc spec:

OS: windows 10 enterprise latest version
RAM: 32GB DIMM DDR3 clocked @ 1333 MHz
VGA: Nvidia GTX 1080 Ti
CPU: Intel Xeon E5-2690 v2
HPz820 workstation kit

here is list of things I have done so far to solve this issue without any result:
-updated all my drivers including windows  to latest. I made sure of that
-tried solving the problem using my friends pc on his  M2 SSD drive to make sure r/w speed or RAM or any hardware compatibility is not the issue
-tried my old graphics card “geforce GTX 680”
-tried disabling anti-virus and firewall
-tried disabling windows UI effects (minimizing windows hardware usage)
-gave unreal engine all administrative right to read and write

things I have not tried yet:
-using earlier versions of unreal engine
-using different OS than windows 10

Thank you for looking into this
Ben