How change Purgeable into TRUE free space Steam recognize?

Just installed High Sierra from Maverick.

I was needing free space to install a game with Steam. I started delete many games from Steam. True free space never increased, only System and Purgeable.

Now when I check Manage Storage for the 1Tb drive:

Application 244Gb

Trash 0

Music Creation 2.46Gb (deleted GarageBand but seems many files still pollute my drive)

Documents 107Gb

iOs files 0

iBooks 0

iCloud Drive 0 (I don't use it at all and will never)

iTunes 3.46Gb despite Optimize stockage is green checked to right mentioning movies and so on)

Mail 13kb

Messages 0

Photo 0

Other USers 0

System 434Gb (sigh)

----------------

Sum: 780Gb

Drive information:

Capacity 860Gb (not sure if already lost 140Gb on the SSD sigh)

Free 334Gb (270Gb Purgeable)

Used 790Gb

Steam logically see only 70Gb free. I deleted more than 70Gb of games a lot more than that, and only System and Purgeable sizes grew up.

I have an obvious huge bug in the absurd drive management, deleted games didn't free space but increase System size and/or Purgeable size.

But manage the drive storage provides no option, I don't use iCloud, already check Optimized Stockage.

What to do from this state coming from an obvious Apple bug, System of 434Gb is lol. And probably minor Steam bug seeing only the true free space.

EDIT: Seems with time the OS is gradually cleaning the non sense garbage lowering slowly Purgeable size and no it's not transfert to iCloud I don't use, still size 0.

Apple Apple Stop this madness.

EDIT2: Well Seems not improve anymore. Now System is 290Gb which is obvious non sense.

I paid this Mac 5K it's not some crap tablet or phone, don't try hide there's files and drive and space, rhaaa.