Unstable with more Gpu, then disconnection

[petrucci90]

Hi everyone,
I'm in that trouble for 3 weeks.
My problem is disconnection unstably. I have 4 cards on my rig and 4 cards working means fast disconnection to me.
Also it could be 11-12 hours stable with 3 cards but could be 1 hour and disconnection too.
I was suspected from psu but i looked with smart plug, it says total consumption is 1000 watt

My cards are 3080,
Biostar tb250 mobo
1650watt uncertificated psu (Rampage 1650w btc)

Thanks a lot...