Im trying to disable pull countdowns in the middle of the screen
I checked on "Do not show user sent timers " in Global Disables & Filters and reloaded but seem this feature not working.
not sure if its buggy or if theres other option i need to click/ click off ?

I should really reword that. All pull timers come from the built in blizzard feature now and they do not want us disabling that anymore. So technically all you can disable in DBM is the features it adds to it (like audio and the timer bar).
You're still gonna get the pull timer itself since it's a core blizzard feature.