yes,
OWL.games don't lie, I lost most of my winnings,
You mean after waiting this long you lose all your earnings that is bad it's a huge amount I don't want to blame you but you should have waited
and congratulations to them, they won. A basic casino tactic is to not pay out the winnings and let gambler play until the winnings are lost.
That's true it's a delaying tactic if they have received the report and shown it and paid you you could have received your payout.
but there are many more interesting details..

This morning I was contacted by OWL.games support stating that I need to sign a contract if I want my payout to be approved. in which I undertake to delete negative comments.
Are you serious?
This is not good it's like bribing you, we gamblers can say what we want to say based on how the casino treat us, no casino should threaten you or bribe you for doing something that is true to your knowledge
P.s For more than a week, we have been waiting for reports from game provider. And now that I've lost most of my winnings, is it enough to sign a contract promising to delete negative comments?
Casinos should be open to criticism and address issues as they come not threatening them to do something