Max Simultaneous Logins

First off, thanks to all the volunteers who are tirelessly helping answer questions in this forum, and a big thank you to the developers who made S2member possible.

In the past few months, a premium member (and some free members in the past few weeks) on my website have been frequently denied access to the website after attempting to login. The error message is as seen in the attached:

Maximum simultaneous logins

After logging in as admin I located the premium user profile with the issue, reset IP restrictions and logged the user out of all locations, and still no avail.

I also went into my S2member pro settings, relaxing all settings around Brute Force/IP login restrictions, Unique IP restrictions, and Simultaneous login restrictions. I’ve reset all of the associated logs as well.

Initially, I thought as well that perhaps there was interference from other security plugins, so I deactivated the ones that detect for registration spam to see if they were triggering the problem.

The only temporary workaround appeared to be deactivating S2member, and logging in with the problematic user account. Upon reactivation, S2member trips up on the login again with the same error…

To clarify, my administrative login doesn’t appear to be affected.

Looking forward to any ideas, and thanks in advance.