Have a membership site set up at [url removed, login to view] using the Wishlist Member plugin. After about 60-70 members joined and began regularly using the site, logins suddenly stop working, except my own cached admin login. Then after a couple days logins begin working again - then off again, then on again. Over the last 5 weeks it's been up and down approximately 6 times - and the lockdown appears to be triggered during the time of each week when multiple members are logging in. The cached admin login will allow editing of protected pages – but not viewing.
I have so far - upon advice from plugin techs - changed hosting companies and restored and optimized the database, to no result, except perhaps a longer interval between "down time."
I need someone with extensive WP, DB, Wishlist Member knowledge to discover the issue and correct it. Would also like to have someone to contact about other projects down the road as this site and others I administer expand.