I’m sure Night will correct me. But the Night follower updater, on a decent hit gets a nice chunk of followers to work thru (on the dropdown/popup) so by the time it’s finished animating them all, a nice new stack is ready.
But Twitch advises that you shouldn’t be hitting more than once per minute on a given end point, as the end point is “static” for that minute and updates once per minute or so anyway. Fugi posts about the “cache” here
Subscribers updates in real time as Night is polling Twitch chat for the “x has subscribed” message in chat.
I have seen the same behaviour you describe, (taking a minute to change) when polling the followers end point. It’s not a fault. It’s just how it works. And other trackers/larger channels just illusion quicker as large channels, get large stacks of new followers per minute, so a queue exists to process the stack.