dig +trace follows the whole chain from the beginning – it queries root servers, then .info servers then your namservers. Thus it avoids any caching resolvers, and also avoids propagation issues.
dig +notrace (the default) queries your default DNS resolver (on Linux, whatever specified in /etc/resolv.conf).
There’s some problem with that resolver – maybe it’s misconfigured, maybe it has old data in its caches, maybe it can not reach your authoritative nameservers, etc.