I get oversaturated images with too much red when using the Make Web Contact Sheet function in Capture One. I use sRGB on a calibrated wide gamut monitor.
Could the display ICC profile be the problem? Or could Internet Explorer be an issue as it is not supporting color-managed sRGB profiles using a wide gamut monitor?
The display profile is not the reason in such a case. The ICC profile for the display tells any application that uses color management what color values for the display should be there. An application that is not color managed (such as Internet Explorer for Windows) would not use the profile and thus the colors would be oversaturated on the wide gamut screen.
When there is a typical gamut display, the colors might not be correct for the applications that are not color-managed. However, a typical gamut display is approximately correct, a wide gamut display may produce oversaturated colors.
The applications on macOS, including web browsers and OS utilities, are color managed, so this issue is not frequent for Apple computer users.
If you use the Firefox browser, you can install a plugin/add-on Color Management (0.5.3.1-signed) which helps to display the colors correctly. Download Color Management for Firefox.