FWIW, here is my ActualBudget Caddy config.

budget.example.com {
    reverse_proxy actual-server:5006 {
        header_down -Access-Control-Allow-Origin
        header_down Cross-Origin-Opener-Policy same-origin
        header_down Cross-Origin-Embedder-Policy credentialless
    }
}

Yep, just sharing what worked for me

Yep, Fedora just works. And it doesnt feel as clunky as Mint or Ubuntu.