Device support for SBAS in general can be spotty in my experience, and it seems very transient. One minute SBAS will show up in the app, and another they are gone. It’s also not clear if SBAS “in use” means differential corrections are being applied, or that the device is using the pseudorange measurement from that satellite for the position solution — see https://github.com/barbeau/gpstest/issues/269 for more details.