Legacy LLK not Recognized

I have an Epson 7900 using 700ml ink. Trying to do a cleaning I needed to use a new LLK 700ml cartridge and so removed the current one with a low ink level. When replaced I get a message that the Cartridge needs to be replaced, and an x in the LLD screen where the LLK should be. When I returned the old cartridge, that still had ink in it, I now get the same message, even though it was fine before it removed. I have reviewed your previous replies to the topic “LLK Not Recognized” and wonder if this is a different situation from that. Thanks