dialog boxes not rendering as should

juat finnished installing mojave, and most thing are working ok.

when started installing apps, I've got this strange thing where the login dialog boxes are showing up empty.

any idea ?

spec: ASUS Prime H370M-PLUS | i5-8600 | UHD 630 iGPU | 16GB Mem

https://i.redd.it/zg3eksddme421.png

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