Again, I would ask same question - does MACSEC switch to client work without 802.1x involved? You proven 802.1x works without MACSEC, yes?
Only other option I see for you is to open a TAC case. I know that for MACEC client to switch, Cisco Anyconnect was used as the client SW, but I doubt if 802.1x was also tested with this combination. I am not even sure Cisco Anyconnect with MACSEC enabled supports 802.1x at same time - does it? Have you tried this with say Windows machine and does this work?