My first guess would be inbound to SFO was on LH metal too, but I'd like to give the OP benefit of the doubt, and we'd all be able to help more once more details are known.

On another note, unfortunately, lounge access is not always as easy as a one-line rule, so understandably, confusing to many who are not well-versed in it. Hopefully, OP will come back with the relevant details so we can help them understand what might have occurred.