If you haven’t paid your RPRF fees yet, wait for the request (mine came one month after MEP). Usually when you receive that, eligibility has been marked as recommend passed or passed nowadays. That I think, is the best time to call IRCC for the first time as there’s a genuine update on your file and you can mention to the IRCC call center agent that you received an update to your file and would like to know what’s that about (as some IRCC agents wouldn’t even bother opening your file if it has not reached 6 month processing timeline even if you insisted on asking for specific status of each step). If you get ghost updates, that’s great, as you can use that as a trigger to call IRCC, I myself have had 3-4 ghost updates and that helped me gauge which steps of my application was cleared.
if you’re asking “best time to call” as in actual time, I’d say try 5 min before 8 am local time, so you’ll be the first on queue. There’s also a callback feature for in-Canada applicants, so IRCC will call you back once your phone number reaches the top of the queue (usually within 30-40 minutes).
