Slash Blast dc

Hi!
My ign is iMayo, my job is a crusader.
ever since the valentines event i keep getting dc constantly while using slash blast.
its so bad i might get 5 dcs in 10 minutes.

i tried investigating a little to see what causes the problem,
not the firewall/ antivirus.
not the valentines new NX.
not being in a specific location - this happens anywhere.
not using final attack (i heard its a buggy skill but its doesnt cause my dc)

i isolated the cause being 100% the slash blast skill,
but this causes an issue for me being still a low level im supposed to use this skill frequently,
making my crusader pretty useless sadly.

i'd love if someone can look at my inquiry and hopefully solve this.

thanks alot!