verified on version:

# rpm -qa|grep ovn
ovn23.06-23.06.1-60.el9fdp.x86_64
ovn23.06-central-23.06.1-60.el9fdp.x86_64
ovn23.06-host-23.06.1-60.el9fdp.x86_64

# ovn-nbctl show
switch 67b10d33-d9ab-40dc-abb8-947b167b37e3 (ls)
    port vm1
        addresses: ["00:00:00:00:00:01 42.42.42.2/24 2001:1::2/64"]
    port ln_p1
        type: localnet
        addresses: ["unknown"]
    port vm2
        addresses: ["00:00:00:00:00:02 42.42.42.3/24 2001:1::3/64"]
[root@dell-per740-53 ovn]# ovs-vsctl show
a7431062-3598-42eb-9f5b-7e00ea05397e
    Bridge nat_test
        Port ens1f1np1
            Interface ens1f1np1
        Port patch-ln_p1-to-br-int
            Interface patch-ln_p1-to-br-int
                type: patch
                options: {peer=patch-br-int-to-ln_p1}
        Port nat_test
            Interface nat_test
                type: internal
    Bridge br-int
        fail_mode: secure
        datapath_type: system
        Port vm1
            Interface vm1
                type: internal
        Port patch-br-int-to-ln_p1
            Interface patch-br-int-to-ln_p1
                type: patch
                options: {peer=patch-ln_p1-to-br-int}
        Port ovn-hv0-0
            Interface ovn-hv0-0
                type: geneve
                options: {csum="true", key=flow, remote_ip="20.0.62.26"}
        Port br-int
            Interface br-int
                type: internal
    ovs_version: "3.2.2"
    on this env, add qos to vm1
ovn-nbctl set Logical_Switch_Port vm1 options:qos_max_rate=2000000
  ovn-nbctl set Logical_Switch_Port vm1 options:qos_min_rate=1000000
 
 
 on the unfixed version:
 
 then we can check qdisc on port ens1f1np1
 
 no class htb
 
 
 on fixed version:
 # tc class show dev ens1f1np1
class htb 1:1 parent 1:fffe prio 0 rate 12Kbit ceil 34359Mbit burst 1563b cburst 0b 
class htb 1:fffe root rate 34359Mbit ceil 34359Mbit burst 0b cburst 0b 
class htb 1:2 parent 1:fffe prio 0 rate 1Mbit ceil 2Mbit burst 1564b cburst 1563b 

change the qos set,
# ovn-nbctl set Logical_Switch_Port vm1 options:qos_max_rate=34359260000
# ovn-nbctl set Logical_Switch_Port vm1 options:qos_min_rate=34359260000
# tc class show dev ens1f1np1
class htb 1:1 parent 1:fffe prio 0 rate 12Kbit ceil 34359Mbit burst 1563b cburst 0b 
class htb 1:fffe root rate 34359Mbit ceil 34359Mbit burst 0b cburst 0b 
class htb 1:2 parent 1:fffe prio 0 rate 34359Mbit ceil 34359Mbit burst 0b cburst 0b 

set verified.

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (ovn23.06 bug fix and enhancement update), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2024:0391