What type of bug are you reporting? Client
What is the bug?
Encore's gen 2 and 3 description on the site states that it lasts 3-6 turns, but according to bulbapedia, pokemondb, in-game description and behaviour, and PS behaviour, they can last 2-6 turns.
See also https://play.pokemonshowdown.com/battle-gen3randombattle-2493929003 turn 13-15
Are you able to replicate it? If so, how?
Boot up a gen 3 game with encore mons and try to force a 2 turn encore and/or use /dt2 encore and /dt3 encore
What is the bug?
Encore's gen 2 and 3 description on the site states that it lasts 3-6 turns, but according to bulbapedia, pokemondb, in-game description and behaviour, and PS behaviour, they can last 2-6 turns.
See also https://play.pokemonshowdown.com/battle-gen3randombattle-2493929003 turn 13-15
Are you able to replicate it? If so, how?
Boot up a gen 3 game with encore mons and try to force a 2 turn encore and/or use /dt2 encore and /dt3 encore