I'm using s2member plugin and Simple User Listing plugin on a project.
But Simple User Listing search function doesn't work after activating the s2member plugin. I informed about this to Simple User Listing plugin author and her answer was
If it works without S2 member, but doesn't with S2 member, then the problem is likely with S2. I'm not familiar with S2 hardly at all, but I just looked at their code and they definitely are filtering pre_user_query with some hard-core code. Something in their plugin must be conflicting, there really isn't anything I can do about it from my side. Have you contacted their authors?
Let me know what is the reason behind of this issue and how to avoid this? Because, I need to use s2member and Simple User Listing plugins both. Since my project has more than 5 user roles I must go to pro version of s2member. Before I go to pro version of s2member, I need to know whether you have any solution for this.
I hosted a sample application in a free hosting account for your reference. It will be automatically expired after next 2 weeks.