Hello,
I have a Windows 10, that cannot handle the USB-C to USB-C connection, it simply freezes when I connect a Dell U2719DC Monitor to the computer.
I already update both Windows 10 and ATI graphical card, and nothing.
Also tried to use a display port from USB-C to HDMI, and here seems to work 90% of the time but I have encountered random behaviours from it like, rebooting Windows 10 in an infinite loop, and also freezing Windows.
Seems like there is a problem in my Windows 10, when using the USB-C as a display port, but dont know what can be. In this machine I only have 2 USB-Cs, there is no other video ports like DP and HDMI, its an iMac.
Imac's are supported by Apple. You may get someone here with knowledge but these are USER TO USER forums not AMD support so I would suggest if have not already, to ask Apple Support or ask in a dedicated Mac Forum and also ask Dell you monitor maker. Also not sure what hardware you have as I am unaware of any ATI hardware in macs that are even currently supported with Mac. AMD bought ATI many years ago. So it's been about 10 years since an ATI card was in any mac I believe nothing past the HD 4xxx series. And none of them had USB-C as it didn't exist yet.
Plus know that even in Windows in Boot Camp that the supplied driver is supported by Apple not AMD and is provided on AMD's site as a courtesy to Apple and it's user but is in know way different than the one on Boot Camp.
It is also pretty well known that Apple doesn't really care if you Windows 10 installation doesn't work right on their hardware either, from their viewpoint it is a reason OSX is better. So they don't go too far out of their way to fix Windows driver issues that they actually control. But do let them know your issues.
You can also talk to actual AMD support through this form: Online Service Request | AMD