So since it seemed that all of this started after a failed upgrade, I decided to update to the current beta version. It took quite a while to update but now everything seems to be in order. I will update you once more if I run into any more issues.
When logging in to the AdminCP, do parameters will be stripped from the URL. This is intended to help protected administrators from making unintended changes on their site by following a link (or being redirected) from a malicious source.
We may be able to revisit this behavior in a future release now that stronger CSRF protections are in place. In the mean time, your only option would be to use a custom controller and put your actions in the manage method.