Version 1.5.1 installed

After having restored a database backup (database backup was working with 1.5.1) I encountered a number of issues:
1. When going to admin page it displayed message requiring databse upgrade from 1.3.9 to 1.5.0
2. Items could not be added to card and users could not login. Both situations caused Whoops Timeout error.

I fixed part 1 by upgrading database only using ZC_install and am now current to 1.5.1 but I am still encountering session issues.

I have not made any changes in configs, PHP or other files. HTTPS seems to be fine.
URL for website is
HTML Code:
Here is Admin-Sessions settings
Cookie Domain True
Force Cookie Use False
Check SSL Session ID False
Check User Agent False
Check IP Address False
Prevent Spider Sessions True
Recreate Session False
IP to Host Conversion Status true
Use root path for cookie path False
Add period prefix to cookie domain True

I have also checked Sessions SQL table and the sessions are created there.

Any advice is greatly appreciated!

Thank you!