Me too.
Once I put %teamcity.pullRequest.number% and %teamcity.pullRequest.target.branch% into my Command Line step TC adds them to “Configuration Parameters” like:
teamcity.pullRequest.number Edit undeletable
teamcity.pullRequest.target.branch Edit undeletable
and doesn’t allow to build this Job because of ‘none agent is matched to this job’.
After I remove %% chars – job reacts to MR successfully.