I would like to encourage other players who happen to end up playing on EU4 and witnessing things I've explained in this thread to write their own experience in this thread and provide screenshots if they can.
Also want to ask admins Dood and Sir_Ironlake who play there often why aren't they warning those players to stop with forced duels?
Everyone has right to play how they want to and forcing duels on other people isn't the right way. They are even interrupting people who aren't interested in their little dueling at the end of the round business and that's griefing.
So far, prime suspects are already mentioned CamelKnights (ROBINHOOD and his friend TUTTIRITARI) and 22nd_aLdraNer (or something like that, I really can't remember exact name).
There isn't many people who are doing this, just four or five but others are following their lead. Punish those who are doing this and this won't happen again.