In Server Configuration > Index do you see anything wrong in Indexing Engine section ? 

Actually, now that I look for the 10th time. I see Indexing Threads = 0 on that page. Default is 25, says range of 4 to 999. Maybe I need to set that to 25. Other than that, things seem to look OK. 

On your server configuration, index tab:

1. Is solr9 the only indexer listed
2. What does it say under Active index engine, and connectivity?

Correct, with 0 indexing threads, there will be no indexing. Change it to 25. 

I noticed this in the solrcloud.indexing.properties file.. it says added yesterday (i upgraded to 24.2 yesterday).. so not sure if that Indexing=0 is new (and supposed to be there from the upgrade?). any idea? Needless to say, if hasnt indexed anything new since April (verified by viewing the date/time modified on the index files). 

# This can be used to set the number of threads to be used for indexing
# This has a valid range of 4-999
# The default is set to 25
# This can be set from the index tab in ServerConfiguration page
# indexingThreads=25
#ADDED: (Tue Sep 17 08:14:17 PDT 2024) indexingThreads=0
indexingThreads=0

Yes, see screenshot from other response. Thanks!

You see, that in the config file you have indexingThreads=0 twice. The problem is there from upgrade to 24.1 .