Missing pages when lots of them are unread/refresh required

I just tried to catch up on el goonish shive: El Goonish Shive
I read about 20ish pages, things felt weird/like something was missing.
It did feel like they were in the right order (not going backwards) but it felt like things got skipped.

After I ran out of new items (“J” to go down), I had to refresh (shift up, shift down) and then I saw a bunch of pages that were basically skipped previously.

I’m not sure which pages I read earlier, but these are what’s left

Maybe this is related to premium archive tier?
I’ve seen a lot of times where on the left it says I have X unread, but the scrolling menu has significantly less than X (and when I’ve marked them all read, if I refresh I get more)

I also get this almost on the daily, if there’s above a certain number of posts, not all of them will appear. I’ll read some, refresh and then some of the missing ones appear, and it’ll be out of order. This might have to repeat a few times to get to see all of them. I imagine that’s super frustrating with something that’s meant to be serial

This is a breaking the basic reason I upgraded to Premium Archive :frowning:
It’s tough to really solve myself cause I think it takes > 2 weeks (usually a lot longer) to collect anything with that many items. and then I’ll forget.

This is especially bad when I have many posts in a single item, like on an active tumblr feed.
For example Knit Me A Pony: Status Message Here