Stuck in login loop when connecting via HTTP

[ApM]

Cacti Version: 1.2.15
Ubuntu 14.04
php version: 5.5.9
MariaDB version: 10.0.38
RRD Tool Version: 1.4.7

I am having an issue logging into my cacti server when not using HTTPS to connect. The server has been running for a while now with no issues. I configured apache to allow https connections this afternoon. After doing so i am unable to login when connecting via http. I get to the login page fine using http and enter the credentials, which according to the cacti logs are accepted, but it doesn't load the console screen, it just stays at the login form. This is the case for all users, and every browser and PC I have tried.

If I connect via https, then I have no issues logging in under any account.

I have seen issues with login loops reported here before, but there has never been a clear solution, and none of them ever mention the issue being restrained to only http before. I have attempted some of the solutions in those other forms, upgrading the database, enabling php session auto_start with no luck.

If I remove the original apache configuration that started this, the login issue persists.
I do not have "Force Connections over HTTPS" checked.

I do not see any errors in the apache error logs.
I do not see any errors in the cacti logs. When a user attempts to login, I only see "AUTH LOGIN: User 'admin' Authenticated", but the user does not get past the login screen.

Has anyone experienced this issue before. Or has any suggestions on where to look.

[ApM]

It looks like the issue was with the php.ini session save_path. I changed it to /tmp and after deleting cookies again, seems like it's working.

[TheWitness]

My guess is that you may have changed the Apache account to something else and did not update the permissions on /var/lib/php/session directory.