WoW Classic 1.12.1 private server, enchantings stacks

[ForBetterDays]

Hi all, am playing on one private wow classic server which have very good antihack system
and am really surprised i didnt get cought, its been a months now since i started to use this bug:

Something happened with my character(NF) when I was doing some enchantings.
I enchanted head and legs with +100 HP. Now, everytime I log out and log back in while my enchanted head and legs are equiped I get +100 HP extra.
It also works with +8 to agi/str/int/spirit +1% to dodge/attack speed etc. Everything stacks in a way that I just put desirable enchant on head and legs I log out than log back in
and it stays like its glued to my own character even when I remove my armor.
Every different enchant stacks but the same doesnt for example: I enchanted my helm with +100 HP, logout/login, I have +200 HP instead of +100, I remove my enchanted helm
I still have +100 HP, than I put second helm and enchant it with +8 stamina, logout/login, I have +16 stam instead of +8 stam. +100 HP from before thats 260 HP( 180 HP extra)

It also works on Wizard Oils and Elemental Sharpening Stones for weapons. (+1% spell crit chance 36 SP, +2 % melee crit chance, etc.)

If my character die bonus hp/agi/str etc is lost and I have to logout/login again to get it.

I do remember circumstances in which this "bug" has been created:
Laggy server, bad server router and mine actions: shadowmeld-enchant-hearstone-server went dc(or I logout dont remember)

I would love to hear from somebody willing to explain what he thinks or what he definitely knows what actually happened with my character.
Every information for me is valuable.

Since am not familiar with Game-Client to Server protocols and have hard time learning how "inside" of WoW works I would appreciate any help. Thanks

Note: If some of my text is not understandable or lacking an informations I'll do my very best to retype it more clearly.