There is a topic full of things recommended to do...or not.
One of the "or not" is using vlan id 1, don't do that.
Change this:
/interface vlan
add interface=bridge-lan name=vlan30-iot vlan-id=30
/interface bridge vlan
add bridge=bridge-lan vlan-ids=1 untagged=bridge-lan,ether2-LAN,ether3-LAN,ether4-LAN
add bridge=bridge-lan vlan-ids=30 tagged=bridge-lan,ether4-LAN
/ip address
add address=192.168.20.1/24 interface=bridge-lan
add address=192.168.30.1/24 interface=vlan30-iot
To this:
/interface vlan
add interface=bridge-lan name=vlan20-home vlan-id=20
add interface=bridge-lan name=vlan30-iot vlan-id=30
/interface bridge vlan
add bridge=bridge-lan vlan-ids=20 tagged=bridge-lan untagged=ether2-LAN,ether3-LAN,ether4-LAN
add bridge=bridge-lan vlan-ids=30 tagged=bridge-lan,ether4-LAN
/ip address
add address=192.168.20.1/24 interface=vlan20-home
add address=192.168.30.1/24 interface=vlan30-iot
While you are at it...I'll search the topic I was referring to.
And...found it:
The twelve Rules of Mikrotik Club - RouterOS / Beginner Basics - MikroTik community forum
Also...more info on VLAN's an be found in this great topic:
Using RouterOS to VLAN your network - RouterOS / Useful user articles - MikroTik community forum