Still getting incorrect sum

See below but seems like you may have already tried some of those. Probably the only way to get to the bottom of it is to share the PBIX or sample source data (see further below). The reason this is going to be challenging is that your measure references numerous other measures and they are all going to have fun issues to deal with like context transitions and, bonus, looks like you are probably using time "intelligence" functions which are temperamental in the best of circumstances (see even farther below). Soo...

This looks like a measure totals problem. Very common. See my post about it here: https://community.powerbi.com/t5/DAX-Commands-and-Tips/Dealing-with-Measure-Totals/td-p/63376

Also, this Quick Measure, Measure Totals, The Final Word should get you what you need:
https://community.powerbi.com/t5/Quick-Measures-Gallery/Measure-Totals-The-Final-Word/m-p/547907

And this one: MM3TR&R: https://community.powerbi.com/t5/Quick-Measures-Gallery/Matrix-Measure-Total-Triple-Threat-Rock-amp-Roll/m-p/411443#M150

Please see this post regarding How to Get Your Question Answered Quickly: https://community.powerbi.com/t5/Community-Blog/How-to-Get-Your-Question-Answered-Quickly/ba-p/38490

The most important parts are:
1. Sample data as text, use the table tool in the editing bar
2. Expected output from sample data
3. Explanation in words of how to get from 1. to 2.

See if my Time Intelligence the Hard Way provides a different way of accomplishing what you are going for.

https://community.powerbi.com/t5/Quick-Measures-Gallery/Time-Intelligence-quot-The-Hard-Way-quot-TITHW/m-p/434008