Basically, on any private servers, they nerf the internal database files in order to get a specific quality of gaming which they prefer to deliver it to the community. that includes drop rates/skill effects and even damage count on executing each skill regardless of the stat build of the character.
/ Skill Trap Type
// On official servers if a unit is completely immune to knockback, it will still walk to the last target tile before
// stopping when inflicted by a stopping status effect (including traps like Ankle Snare and Spiderweb). All traps on
// the way will be activated.
// This does NOT include being immune to knock back from equip. This bonus only helps against knockback skills.
// 0: (official)
// 1: Stop effects in GvG/WoE make units stop immediately.
// 2: Stop effects make monsters immune to knockback/bosses stop immediately.
// 3: 1+2
If we; or I mean, if they would intend to change the “skill_trap_type: 0 to => blank 3”, That will change the entire concept of the trapping field. Bosses won’t move a bit until you think of stopping, and if that specific monster was an IN-GAME player he would just go blank DC (Alt+F4) or He would just start asking your IRL address.(old school pvp scenarios but yeah), it can be changed but still, it’s the decision of the Admin whether it’s a GO or NO.
PS: They could have nerfed it.