Google Analytics audience data isn't passing to Google Ads

I'm creating a remarketing audience list in Google analytics and after setting audience definition when I add audience destinations, I only see 0 as the audience size in google ads. In google ads, it keeps showing me the audience list is too small. But even if I try to retarget a subdomain, it still shows up too small. It happened since last October. Did Google change any configuration or algorithm? Thanks all!