Cannot access libraries on local network after router dns update

Plex Media Server
,
1

Server Version#: 4.156.0
Player Version#: same
<If providing server logs please do NOT turn on verbose logging, only debug logging should be enabled>

I have been running my server fine for a while. I updated my router (tp-link omada) setup to route to public dns cloudflare (1.1.1.1) to become the default DNS.
So basically I edited my networks/vlans, so default DNS is 1.1.1.1 and other is 1.0.0.1

Since then, I cannot connect to library on all my devices.
And even if it shows, no playback can happen (I get error when playing, but browsing library is fine).

What should I do? I appreciate the help

Settings:

Allow incoming insuecure connection, and preferred.
Both server/devices (e.g. LG TV) are on same VLAN and subnet.
I tried fixing IP in LG TV app to the server IP, and I can see libraries and browse them, but no playback happen (I get error)

2

OK, so I tried different things… when I disable cloudflare dns from the router for the VLAN, plex stops working

How do I make sure that routing local stays local and doesn’t go over the internet (if that is what is breaking my plex)?