It appears to be an escalation of the time-based shifts that have been present in Luceti.

Locations have already been reverting to their past forms. With that logic, it's not hard to connect it to past residents reappearing, if only in an utterly intangible state.

There are only two options for dealing with this. One is to observe them at every given opportunity and collect data to see if there are any variations. If there truly is no way to reach out to them.

The other option would be to avoid them entirely. It may prove more beneficial for one's mental wellbeing.