Spotlight will not index external drive

Mercury Elite Quad Pro external USB - C 3.1 drive enclosure with 4 SATA Hard Drives in it. M4 Mac mini with 512GB storage. Running Mac OS Sequoia 15.3.2. External hard drives are now unsearchable after update. Tried all the usual techniques - adding then deleting from Spotlight Search Privacy. No joy.

Yes - my drives are named after the Founding Fathers. Rush refers to Dr. Benjamin Rush, signer of the Declaration and friend of Adams and Franklin.

Tried Terminal commands:

• sudo mdutil -Eai off
• sudo mdutil -Eai on 
• mdutil -as

Returned the following:

@-Mac-mini ~ % sudo mdutil -Eai on

/:

Indexing enabled. 

/System/Volumes/Data:

Indexing enabled. 

/System/Volumes/Preboot:

Indexing enabled. 

/Volumes/Adams:

Indexing and searching disabled.

/Volumes/Adams - Data:

Indexing and searching disabled.

/Volumes/Hancock:

Indexing and searching disabled.

/Volumes/Hancock - Data:

Indexing and searching disabled.

/Volumes/Jefferson:

Indexing and searching disabled.

/Volumes/Jefferson - Data:

Indexing and searching disabled.

/Volumes/Madison:

Indexing and searching disabled.

/Volumes/Madison - Data:

Indexing and searching disabled.

/Volumes/Rush:

Indexing and searching disabled.

/Volumes/Rush - Data:

Indexing and searching disabled.

/Volumes/Washington:

Indexing enabled. 

/Volumes/Washington - Data:

Indexing enabled. 

The mdutil -as command seemed to do nothing.

Any suggestions on how to fix this?