Oh, that changes my answer. per: https://www.irs.gov/charities-non-profits/churches-integrated-auxiliaries-and-conventions-or-associations-of-churches
"Churches (including integrated auxiliaries and conventions or associations of churches) that meet the requirements of section 501(c)(3) of the Internal Revenue Code are automatically considered tax exempt and are not required to apply for and obtain recognition of exempt status from the IRS."
So now what is the next step? If this was my local parish, I would furnish the above information to the investment group.
If that did not work, I would ask the CFO of our Diocese for help in resolving the matter.