I added Joomla's login module to the bottom of the page of multiple menu items and it works reliably on all of them.
I then removed Joomla's login module and added CB's login module to the same pages and it works reliably on all of them.
So that makes me think some other software I'm using is causing this. I'm using Joomlashack's Shack Toolbox Pro to present the login module. It shows a tab on the right side of the screen and slides out to show the module. When using this, I get unwanted redirect results. When using the login modules outside of this, I get expected results. I will contact Steve and the team at Joomlashack to report my findings.
Thank you for helping me walk through this. Sometimes the simplest of testing procedures get overlooked. *insert "dummy" sign pointing at me* lol
