What version of Project ex: 2013 standalone, 2013 server, 2016, project 365?
I’m running 2013 server and the only ways I know of that the OWNER can be changed are
1) the current owner changes it via the PDP page in PWA
2) another resource with Admin security levels changes it in the PDP
3) it is possible an external interface is accessing the project DB and changes it, using an API of some type
General questions that may help others diagnose
Is it always the same name that it is changed to? or Random names?
What is the frequency of changes? Randomly throughout the day? Once a week on Friday night?
Are there any batch or API type processes that run at the same time/frequency as the changes occur?