This just started happening to me today. Earlier autocomplete was working just fine, then anything that had any () in them would not autocomplete the (), and now autocomplete just isn't working at all.

I have the exact same issue - I only started using REPLIT yesterday and this function hasn't worked. Code intellegence is enabled. Reported the bug but very frustrating as I'm still learning Python!

IN settings, you need to enable the thing called 'Code Intelligence'

Go into settings (the gear icon) and enable the last option