grorbabrag

Sweet, just keep in mind that the connection between caddy and actual is just a plain HTTP one. Since your connection is in your local network that's fine, but if you were to change that then be mindful that you are placing an implicit trust on the networking between caddy and actual.

Yea, no, that log entry doesn't really shed any light on the issue.

However, your comment regarding having configured ActualBudget to serve the certificate might be hinting at what's wrong.

Since your chain is client > caddy > actual you should be following the guide by actualbudget regarding operating behind a reverse proxy, so actual should not be serving the certificate.

You'll likely want/need to configure actualBudget to trust your proxy as well https://actualbudget.org/docs/config/#trustedproxies

Seems weird that you're not seeing any logs for service2 in caddy, especially if it's caddy serving the 502. I'd expect at least a message from caddy complaining about being unable to reach the upstream service in that case.

Verify that the 502 is coming from caddy and not potentially some other gateway that's part of service2.