I have what seems to be an impossible question to find answers on... but
here goes:

Background:
I have workbook with multiple pivot tables.
All pivot tables are linked so if you refresh one, you refresh them all.
I have a tremendous amount of data being pulled in, approx 5000 rows, with 47
columns of data. 3 of those columns are formulas in excel that are updated
based on certain data being present.
Data is updated every day, and can be more than 5000 rows or less, it is
constantly fluctuating.
I have a dynamic named data range so I don't have to keep changing all the
pivots / formulas.
On each pivot table, I have groups set up based on specific fields.

Problem:
Grouping.... I used to be able to ungroup my selections, refresh my pivot
tables and regroup the same selections using the same name. My computer was
recently rebuilt, and now I seem to have lost that option. When I ungroup my
selections, the entire column disappears. This never used to happen before.

I don't necessarily want to have this option back, my overall question is
whether there is a way to keep the grouping intact and have it update with
the refresh and not disappear every time? I've looked through many websited
and at least 100 posts on this website and have found nothing even remotely
similar. Is there anyone that has run into this before or am I just being
cursed for making complicated excel pivots? :-( Any ideas (excluding adding
another formula to the data) is greatly appreciated.

Also... because i've seen countless posts with this problem listing... I do
not have errors grouping. I can group just fine, it just doesn't stick
around after a refresh.

Thanks for taking a look, and I hope someone out there is willing to think
about this crazy issue!