network – What do the different Spotlight PolicyProcess types: “mdutil” and “STORE_ADD” do?

I have two volumes both with VolumeConfiguration.plist files:

/Volumes/Media_1/.Spotlight-V100/VolumeConfiguration.plist
/Volumes/Media_2/.Spotlight-V100/VolumeConfiguration.plist

Spotlight works very well on 6TB Media_2 locally and over my SMB network (iMac-ethernet-MacMini)

Spotlight doesn’t work properly on 18TB Media_1 over the same network, but works fine locally (on the MacMini).

I have erased Media_1 and reloaded 16TB of data and rebuilt the spotlight index numerous times and it’s no use. It’s not searchable over the network.

I ran diff on both volumes VolumeConfiguration.plist and what jumped out was the different string in “PolicyProcess”:

diff /Users/john/Documents/media_2plist.txt /Users/john/Documents/media_1plist.txt |colordiff | $(brew --prefix git)/share/git-core/contrib/diff-highlight/diff-highlight
3c3
<         16D4F012-5E09-4D3B-ACD4-6768C0DA2048 = Dict {
---
>         502C691E-AEE5-4729-B540-722F1C681B19 = Dict {
5,6c5,6
<             PolicyProcess = mdutil
<             PolicyDate = Thu Jul 25 10:07:47 CST 2024
---
>             PolicyProcess = STORE_ADD
>             PolicyDate = Tue Aug 27 19:30:08 CST 2024

Using nano I changed the PolicyProcess on Media_1 to “mdutil” and then rebuilt the index but it had been changed back to “STORE_ADD”. That’s how Spotlight wants/needs it.

I can’t find any documentation on this. Why Spotlight is doing it, etc.