I was able to set floor height and grab the cup!
And boy do I hear you on OpenXR... We had some last minute issues with grip button specifically for Oculus Quest Link users. Cross platform VR needs to be easier!
Each time I create a new project I just pull this up: https://docs.unity3d.com/Manual/xr_input.html
But this still only works about 50 percent of the time... Unity whyyy