SQM cutting speeds to a fraction using RB750Gr3

I just got an RB750Gr3 and installed OpenWRT 19.07.8

I have a cable internet connection

Without SQM disabled, I get 574 down and 16 up on dslreports.

When I enable SQM (cake/piece_of_cake) the speeds drop to around 15 down and 3 up.

What am I missing here?

Do I need to set anything in link layer adaptation?

Thank you!