It looks like someone updated a dependency of a dependency of a dependency of PM2 (minimatch package) on the node side in a way that arguably breaks semvar. minimatch between 3.0.4 (previous version) and 3.0.5 (new version released 5 days ago) seem to be breaking for older versions of node.
I saw a couple of other people opened issues against the new version of the minimatch module here with similar issues:
We’re still trying to decide on how to handle it from a fix perspective. To be continued…