I have two different Beocreate 4Channels attached to 2 different Raspberry Pi 4s. Both have optical inputs attached to the Toslink output from a TV. Both can see the "Optical Input" in Adjustments -> Volume Limit. Neither of them show any "Optical Input" at all under Sources, though I did see it there briefly on one of them (not sure what changed). I have tried changing speaker profiles and just about every other setting I can find. Nothing I do makes the Optical Input re-appear.
"Optical Input" disappeared from HiFiBerryOS, input does not work on either of my 2 cards