See attached (cleaned up, confirmed it still works).
Difference I can see: you tag your VLAN-slave interface whereas I use bridge.
And according to this excellent VLAN guide, it is recommended to use bridge, not slave VLAN-itf.
But I could be wrong with my interpretation.
http://forum.mikrotik.com/t/using-routeros-to-vlan-your-network/126489/1
Can you try to do the same ?
# 2023-08-06 11:08:13 by RouterOS 7.11rc2
# software id = BFJX-J8NU
#
# model = RB750Gr3
# serial number = <serial>
/interface bridge
add admin-mac=<admin-mac> auto-mac=no comment=defconf frame-types=\
admit-only-vlan-tagged ingress-filtering=no name=bridge vlan-filtering=\
yes
/interface vlan
add interface=bridge name=VLAN2 vlan-id=2
add interface=bridge name=VLAN30 vlan-id=30
/interface list
add comment=defconf name=LAN
/ip pool
add name=dhcp ranges=192.168.200.20-192.168.200.254
/ip dhcp-server
add address-pool=dhcp interface=bridge lease-time=10m name=defconf
/interface bridge port
add bridge=bridge ingress-filtering=no interface=ether2
add bridge=bridge ingress-filtering=no interface=ether3
add bridge=bridge ingress-filtering=no interface=ether4
add bridge=bridge ingress-filtering=no interface=ether5
add bridge=bridge frame-types=admit-only-vlan-tagged interface=ether1
/ip neighbor discovery-settings
set discover-interface-list=LAN
/interface bridge vlan
add bridge=bridge tagged=bridge vlan-ids=1
add bridge=bridge tagged=bridge,ether1 vlan-ids=2
add bridge=bridge tagged=bridge,ether1 vlan-ids=30
/interface list member
add comment=defconf interface=bridge list=LAN
/ip address
add address=192.168.200.1/24 comment=defconf interface=bridge network=\
192.168.200.0
/ip dhcp-client
add interface=VLAN2
add interface=VLAN30
/ip dhcp-server network
add address=192.168.200.0/24 gateway=192.168.200.1 netmask=24
/ip dns
set allow-remote-requests=yes
/ip dns static
add address=192.168.2.1 comment=defconf name=router.lan
/ip service
set ftp disabled=yes
set www disabled=yes
set api disabled=yes
/system clock
set time-zone-name=Europe/Brussels
/system identity
set name=MTHex
/system note
set show-at-login=no
/system package update
set channel=testing
/tool mac-server
set allowed-interface-list=LAN
/tool mac-server mac-winbox
set allowed-interface-list=LAN
/tool romon
set enabled=yes