This is definitely a bug. It's actually a structural flaw in the app. It should not be offering a different delay time for each mode for each lighting type. There is actually only a single set of delays available.
Another use has suggested many times, unfortunately to my neglect, that delay per mode should be a part of Options for Off, not where it is now in the UI. That user is right, and that is the fix for this problem.
It will be moved to Options for Off, so that there is only a single set of delays, to make clear that they operate on all light types. A CT bulb and a Color bulb and a dimmer should all turn off at the same time in a single ML rule. Needing different times for different light types is beyond the scope of a single ML rule.
Hopefully this will make it into our upcoming 2.1.0 release, or at worst a hot fix update to it... Stay tuned. Thanks for doing the heavy lifting of exposing the root cause of the problem you were having.
