We just upgraded to 7.8 (from 7.6.2) and we noticed something odd with Timelion. It appears that it's ignoring interval settings. Normally we have our visualizations with interval set to 1h, but despite that, TImelion is showing 30min buckets on Dashboard:
When i resize browser's window to smaller one, then it shows proper interval.
Additional note: in Timelion editor, everything looks ok, so it's propably related to Dashboard view only: