BRD ARENA spawn bosses BUG !

Like I wrote I try to find Savage Mail chest armor and almost every day I make in party few times x 5 Arena runs (5 its limit entering for one hour)
So I make usually 15-20-30 Arena every day.
And I saw Orc maybe few times !!!
Even Ogre spawn many times I sold tons belt and rings to npc even I saw spawn Ogre 3 times in row.
But usually is Spider bos sometimes x 4 for each 5 runs !!! Or many other.
But most days after make 15-20 arena run I NEVER SAW ONE ORC !!
This armor have 8% drop but IF I meet the Orc Boss !!!
BUT If he dont spawn I have 0 % chance !!!
I lost almost 2 months to find Savage Chest armor and make about 300+ BRD Arena runs and I saw ORC maybe 5-8 times for 300+ runs !!!
I read/heard that bosses are RANDOM and no have bigger % chance to spawn than other so what its even possible !!!
Blizzard give me back 150 hours farming arena BRD on this bug when I can even SEE the ORC !!! Why I saw 150 Spider boss for each 5 Orc boss ???

In WoW Classic I forgot write.

And what about this bug?
Still dont know why I saw few Orc boss on 300 runs and its mean 40-50 different bosses for one Orc boss.
My party gear up at least 20 spell dps with Ogre belt and ring and I heard that Ogre is rare boss lol its not true I saw Ogre 10-15 time more than Orc.

I can deal with drop savage armor is 8% but I need meet the mob which drop it first !
Or maybe exist a list with % chance for every boss and Orc have 5% chance for spawn ? I dont know tell me.
Its not “rng” its a huge bug.
Any “blue” official answer ?

There’s not much we can really look into here as we don’t get things like lists of drop percentages or spawn percentages, etc. Neither do our Game Masters through the ticket system.

Best thing to do would be to report this issue using the ingame bug report tool. That way your report goes directly to the developers who are maintaining the game and allows them to look into the arena boss for Blackrock Depths.