I ve only been using VR for about a Year now have Quest 1 Quest 2 and Pimax 5k+ . I didn’t have an issue with nausea while in VR till recently I changed my IPD settings. After I figured it out I carefully went back took the IPD more seriously and changed my settings in the PIMAX. Problem solved for me. So if you strangely start to have nausea the first thing I would check is your IPD settings. - Just wanted to contribute to the forum. Hope this helps some people that run into this problem.