It’s Nigerian pidgin and literally every Nigerian born person who speaks English will say itNo shade but I’m almost positive “tiyad” is patois as a Jamaican myself. I’ve never heard a Nigerian say that
Ik there is a lot of patois that has turned into general black British lingo, but specifically over the past few years there has been an influx of African specific phrases that have been adopted. Such as tiyad, embarrazzed even the “soft life” concept is Nigerian and most people inc grace use that very incorrectly