Update previous calculations always?

Not sure if this works but there's a setting in the calculated field settings area (checkbox) that says Update Previous Calculations (in the background). I was trying to figure out what that was for when I came across this so I am not certain but try that?

I would first try making your calculation even simpler. Maybe just make a test field and put in this calculation -- Resolve Project.Planned Completion Date, and see if that will work? [Whoops nevermind, just tried and that doesn't work]

Other than that, I know certain fields just won't recalculate (unless you resave the form that is on the object). So you might just be SOL.

Just to chime in here... remember that a calculation only updates when the object the field is on is updated.

This means, just because the Resolve Project has a new Planned Completion Date due to a change, the issue and its calculation don't update right at that moment.

Now, once the issue is edited, it will then go through the calculation and update so the Resolve Project's Planned Completion Date is updated. Now you can manually edit the issue OR... you can 1) go to the three dots and click Recalculate Custom Expression, or 2) wait overnight if the project's status equates to Current (and update setting is Automatic and On Change)

This is why I like to do a bulk edit and recalculate custom expressions on big executive reports before any big meetings. (NOTE: This also is an issue when working with cross project predecessors. Bulk editing and selecting recalculate timeline is very important)

Hope that makes sense.