Totem Two Trees S speed

Hey
When I get above 1000 speed with lightburn, it doesn’t laser.
someone with such a machine can speed 6000 or 9000, why is that ??
Totem Two trees S.
both at mm / min
Thanks

Have you reviewed our GRBL setup guide as a starting point?

https://lightburnsoftware.github.io/NewDocs/CommonGrblSetups.html

This explains your speed limit issue:

Thanks for answer