Unclear runner status warning

I have created a runner and see the strange status icon

gitlab-ci-multi-runner verify shows that everything is going fine. What does it mean? Where can I found any logs or description?

I tried to use this runner for build but received a message that my build is suck.

This runner has maven tag, but something is going wrong. Could you please help to find logs or description of this warning?
I guess is better to provide some kind of insinuation for runner's warning icon.