Solved
_mkto_trk_http cookie??
For some unfathomable reason it seems since the 48th week of 2021 we are getting a _mkto_trk_http cookie instead of a _mkto_trk . O other cookies do not have a _http postfix. Both client and server side shows this consistently. I am nonplussed. Did anyone else see the same? Is this a setting in Marketo maybe ?