Dispute can be defined as a situation where users(buyer or seller) raise an issue stating that they have not been honoured with the funds which they are entitled to. Apart from this, there are several other situations which can be termed as a dispute where a discrepancy is noticed in the value of the asset which has to be transferred, difference in the time period of transfer etc.
You can raise a dispute after the timer on the trade runs out. If you'd like to raise a dispute after the trade is done, please raise a support ticket.
For more info check - https://koinex.in/loop/Dispute_Resolution_Guidelines