iThemes Security Values Swapping Between Sites

I have 15 sites installed (all with Easy Engine) on my Ubuntu 16.04 server, all with iThemes Security installed to hide the back end and add other security enhancements.

On multiple of my sites, every once in a while (about once every 1.5 - 2 weeks), the back end login URL’s will swap between sites. For instance will switch with So to log into site 1, i’ll need to go to Since I have 15 sites, it takes a lot of guessing to figure out which values have been switched where. This also switches the logging output from site1 to site2, making it nearly impossible to debug problems.

Is this an issue with having caching enabled on all sites, and the cache is being swapped between the sites? This is a huge security risk, and I want to know what needs to be done to prevent this ASAP, so I don’t compromise users’ data.