About Andorid Work Profile Creation Issue

Hello,

This is my first message on this forum. Greetings to all first.

I am having problem with Android for Work concept. I am using Galaxy S7 Edge(G-935F) and i cant create Work Profile. I rooted my phone 1 month ago and a moment later i decided to recover my phone, formatted all internal storage and did a clean recovery. I tried to create Work Profile last night and i got this error:

"The security policy prevents the creation of a work profile because a Custom OS has been installed on this device."

My device status was showing up as Custom. I made a search and figured out that i can make device status to original again via flashing stock firmware. I found a suitable stock firmware for my device from SamsMobile site and flashed my phone according to instructions. Now my device status seems as Official. But i cant create a Work Profile still, getting same error. I dont understand what is the reason of this.

I doubted Samsung Knox of blocking this but learnt that Samsung published a video on their YouTube channel telling Knox is hardening Android for Work. So i couldnt find a possibility which can cause this situation. I would be so grateful if i can learn what i can do to fix this issue. Will be waiting your sights.