Another Holo May owner here. Assuming you have either the L2 or KTE versions you probably want to use the USB input for your favorite source anyway. As I'm sure you know, the May is one of few DACs that have next-level USB implementation with full galvanic isolation. If you're already using that and looking to connect a second or third source then I can sympathize with you as I also had I2S issues trying to connect a HiFi Rose 130. I finally hit on a combination that worked (both units are configurable) but found I preferred USB. As soon as I modify my Oppo to have an I2S output I'll be trying it again. I'm normally an I2S evangelist.
I2s cable not working with my DAC
I just received my new HALO MAY DAC and in trying to hook it up to my PS Audio Airlen’s I get no sound with the I2S connection. It works fine with a digital cable hook up. The same thing happens with my CD player trying to use the i2s connection. I’m befuddled.