This may depend on the amount of channels you're subscribed to. I've got a lot of subscriptions (423) , split mostly between music and educational channels. So

This may depend on the amount of channels you're subscribed to. I've got a lot of subscriptions (423) , split mostly between music and educational channels. Some of the channels that post less frequently just don't show up in my feed at all, which happen to be the more educational ones that I interact with the most. It is known among content creators that Youtube's algorithm highly prefers frequency and consistency, and I suspect that includes the subscription feed in cases where some results are omitted. I've gone to channels manually and realized I've missed the last five or six most recent uploads so many times now, and I check the subscriptions page almost daily and have been, for a long time. On a side note, my bookmark points right to the subscription feed, because I think the homepage is an abomination. I can only recommend that to anyone.