There are at least 5 different point I have been able to identify that I'm mentioning here.
1. When you subscribe to a new channel keep in mind sometimes even if you subscribe with two arrows up, some scenes will show up in the "New Scenes" section, and others will show up in the feed section, depending of your browser.
New releases:
Feed:
2. There are situations where the scene will not show up at all, in neither one, like it happened to me with the following scene, but by clicking on her name I was able to discover there was a recent scene by the model. You may get many updates from the same studio, but not all the scenes will always show up.
3. Some studios, even if you're subscribed will not appear on neither the feed or the new releases tab, so you may have to check if they have updates, like it happened to me with 4 of this studio's updates.
4. Other times there will be a model you like that may have different pages. So for example here, this model has two different pages, so if you are only subscribed to one, you will miss on her other scenes. It is better to look for her in the search bar, and subscribe to her other pages or you may miss on new releases by her.
First page:
Second page:
5. From what I heard, and you should consider I could be potentially misinformed, the studio and model gets upvoted with your purchase as long as you buy within 14 days of the release date. After that, I believe the scene still gets some recognition, but it isn't direct. So you may keep that in mind when you want to support a particular model or studio.
Keep in mind this is only my experience, and you may have a different experience than mine.