Nicolas, as you get more miles on that loco, that should loosen up. I had this issue on my USAT PA units… everything else ran… lubed them and they were perfect.
I would definitely look at the turnout anyway, check the gauge through it, etc.
By the way, was the metal on your “bracket” as “pebbled” as in the picture I posted (Which is actually Ted’s loco!), or was it nice and smooth?
Greg