Trading after stock hitting Upper Circuit with No offer seen?

At 11.20 am today(11.5.21),Trident stock hit Upper circuit at Rs.18.40. After that we can see only Bids
(with max. bid of Rs 18,40) and no offers/orders on sell side.
But still we are seeing the trading is going on with increase in Vol, change in LTQ without any visible entry
on offer side.
How this is possible? Who is buying and who is selling?

Market order