I'm an elementary OS 5.1 user, and I self-host a few different applications including Jellyfin and Nextcloud on another Linux machine.
Because I didn't want to have to use a different endpoint URL for these applications at home than I do in public, in addition to a public DNS record with my domain registrar, I created a duplicate sort of DNS entry at home with my local DNS server.
jellyfin.example.com resolves to 192.168.1.101 when using local DNS server.
jellyfin.example.com resolves to 220.127.116.11 when using public DNS server.
My issue is that when I first connect to my home network, it is resolved locally as I expect. After about 15 minutes or so, it switches to being resolved publicly, which then cuts off my ability to access using the fully-qualified domain name. It continuously switches back and forth every few minutes. As of right now, I have no clue why.
How can I tell elementary OS to use the local DNS server when I'm at home, and the public DNS server otherwise?