Hi and forgive me for not understanding what I am doing...queues are a pita for me. I have never gotten any of them to work. Maybe partially a few times but never completely locked down to a speed limit.

Here's what I do:
Fresh factory reset hEX. Got in with webfig this time, winbox some other time. Changing my wan to lte1, so now I only use port 2-5, and that's fine.

Deleted fasttrack.

From there I want to cap port5.
Go to queues, add, set target to lan5 on both rx&tx, set all speeds to 5M, burst time 30. Don't set any days and other timings. (No setting = all the time I hope). Set max and total max to 5M too. I do not do anything with packets or destination.
Activate the queue, it says not invalid, and light green

...and do absolutely nothing. Speedtest says 26Mbit on Lan5

Oh, and it strangely adds a new target, also lan5.

Latest stable fw. Did not reboot or powercycle.

Please explain this to me like I'm a bit daft. Hammer it in... How do you make a working queue for a lanport?

try limiting by vlan, bridge or by ip address whatever you use