Unable to wifi stream to Ropieee plugged into SU9 DAC

Hi, I’ve been trying to figure this one out for a week now, and hope to get some help.

I have the latest Ropieee version running on a RPi4 that’s plugged via USB to an SMSL SU9 DAC. The RPi 4 is connected to my LAN via wifi through the built-in wifi chip.

Everything was working fine till about a week ago when it suddenly stopped working. I would select the Ropieee endpoint (which Roon is able to see), the playback will try to start and will just stop. The endpoint will then disappear from Roon for a short while before reappearing again. If I try again, the same thing happens. I have reflashed Ropieee a couple times now and still the same issue.

I have also tried swapping RPi4 hardware with another endpoint that I was using, and it gives me the same issue, so I don’t think it’s a problem with the wifi on the RPi4. Nor do I think it’s a wifi signal strength issue as I am able to swap out the SU9 DAC with a Benchmark DAC1 (without changing anything else) and bizarrely, that seems to work fine.

Anyone has a similar (puzzling) experience recently? Appreciate any thoughts or advice. Thanks!