Hi There,
To Clean the transients we reccomend:
Transient Cleaner (https://en-ca.wordpress.org/plugins/artiss-transient-cleaner/).
1. Install Transient Cleaner
2. Navigate Dashboard -> Tools -> Transients
3. Set Clear Expired Transients -> Enable
3. Set Clear Expired Transients -> Clean Now
5. Set Remove All Transients -> Enable
6. Set Remove All Transients -> Optimize Afterwards
7. Set Remove All Transients -> Clean Now
8. Save Changes
9. Recheck your Cornerstone for functionality
Hope it helps.
Joao