This is what happens when you are dealing with Payment for Order Flows. Your orders are internalized by the market maker and not traded on central exchanges where orders are instantly matched when the price matches. With market makers, you never know what can happen.
This kind of s*** happens all the time in retail forex, orders with prices exactly matching the NBBO not get filled, orders got requoted... Looks like the same s*** is plaguing the rest of the asset markets too now.