[2021] Are epic and steam players separated?

I have two accounts. On one steam and another on epic that I use to play with some lower level friends. For fun I decided to take the solos let of the epic account and see how far I could get in my ranking after the placement games. I managed to get D3 div3 after. This did not surprise me due to my steam account being the same.

I wanted to see how many games I could win in a row with winning all 10 of the placements and continued for 13 or 14 games. I ended up getting to C2 in ones. I have never been there on my steam account. Only in 2s. Almost all goals were NOT kick off goals either. My question is this:

Are the two platforms separated?