I was using Sitecore 8.2 then upgraded to Sitecore 9.3, after the upgrade process, when I publish any item, I noticed that the index is not updated, I must trigger a full rebuild for the index to be updated.
I checked the index update strategies, but it's the default ones, I checked the Crawling log file, during the publish process, there are no logs in there, it's like the update index process is not triggered at all, but I found this at the log file after I restarted the instance.
The event queue is enabled, and I tried cleaning it and also the publishing queue, but still nothing happens.
FATAL [Index=sitecore_master_index] Initialization of IntervalAsynchronousStrategy failed because event queue is not enabled.
FATAL [Index=sitecore_web_index] Initialization of OnPublishEndAsynchronousSingleInstanceStrategy failed because event queue is not enabled.