I've now printed a sample photo and compared it with the ICC profile used with the iiyama. Firstly, I noticed that Windows 10 first loads some default profile and a couple of seconds it switches to what appears to be the correct ICC profile I generated. This correct ICC profile might be very different from the one that Windows used at startup. In my case a cool temperature profile is loaded by Windows, only to be replaced by the X-rite created profile 5 seconds later, which is a bit warmer. To make sure which profile is the one I want (whether it's the first one loaded by Windows, or the second one activated a moment later) I printed a sample photo using my wife's heavy duty printer she uses to for her customers, this printer has a very well balanced and profiled ICC used by professional photographers. In my case the second profile (slightly warmer) is a definitive match with the printed sample. It could be that in your case the correct profile is loaded for you but then it becomes even warmer for some reason, the result being some yellowish colour space.
As promised I've now generated a new profile captured at brightness set to 50% at iiyama's COLOR TEMP. set to NORMAL (it's in the dropbox folder).