Hi @Olivier_Le_Rigoleur welcome to the community!
I think the query’s originator is something marked conn43774 from the log line above. To see what connection is named as conn43774, you might be able to search for that string.
For example, if I’m looking for conn10, I would see this log line:
{"t":{"$date":"2022-11-08T16:47:19.858+11:00"},"s":"I", "c":"NETWORK", "id":51800, "ctx":"conn10","msg":"client metadata","attr":{"remote":"127.0.0.1:49995","client":"conn10","doc":{"driver":{"name":"nodejs|mongosh","version":"4.10.0"},"os":{"type":"Darwin","name":"darwin","architecture":"x64","version":"20.6.0"},"platform":"Node.js v16.18.0, LE (unified)","version":"4.10.0|1.6.0","application":{"name":"mongosh 1.6.0"}}}}
which shows what client and what IP it’s connecting from.
disable this feature and have all query plan candidates run on the primary ?
Do you mean to run all queries in the primary? Have you tried changing the readPreference of the application from primaryPreferred to primary instead (the default)? You might also want to double check that no application is accidentally using secondaryPreferred read preference.
Best regards
Kevin