

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.

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 > actualyou 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