I am glad you got the plugin working (marking this as resolved), but I am sorry to hear to you had many problems.
It sounds like the security plugins add extra layers of security to WordPress for redirects to and from the admin pages. I had not considered this before and I am very grateful that you have brought it to my attention.
Would you mind letting me know which security plugins you were using? I will do some research and see if there are steps I can take to make the plugin compatible with the common security plugins.
I appreciate you posting about your experiences and I am glad you got the plugin working.