FYI I think this post is also relevant here:
I heard back from the team, and I’m afraid there isn’t much we can change on this behavior right now. Task indexing after updates happens asynchronously and depends on the current load on the system. Under normal conditions, the process typically completes in <60 seconds, but during periods of high traffic it can take several minutes.
Having said that, I added my vote here to improve the current indexing architecture!