Cboe explicitly defines the difference between the options on SPX as AM-settlement and SPXW as PM-settlement, but for VIX and VIXW, they say they're both AM-settled.
I can see in my trading platform that VIXW options expiring today are still actively traded. Why is that? How can an AM-settled option continue to trade the day of expiration? Unless it's PM-settled and I missed fine-print somewhere?