Seems to be a feature for specific regions, at least at the moment.
In LastCard page there is a link to download a build of Opera with it included and LastCard is mentioned in the Opera 76 changelog.
Thanks for this. Yes, in researching what LastCard was, I noticed the "baked in" version on their home page for download. I'm on version 74.0.3911.218. I'll try "hiding" it again and see if it takes this time, but this kind of auto enabled advertising (with no apparent removal mechanism) is annoying and goes against their much touted ad and popup blocker philosophy. Sacrificing my privacy for the corporate gain is one of the reasons I dumped Google/Chrome. [end grumble mode]