Preflight Checklist

• I have read and I agree to follow the support disclaimer.
• I am sure that my bug has nothing to with third party extensions.
• I have read the troubleshooting FAQs and looked trough the #help-desk channel on the official Discord, but none solved my issue.
• I have searched the issue tracker for a bug report that matches the one I want to file, without success.

What type of Apple device have you encountered the bug with?

iPad

Operating System Version

iPadOS 17.3

App Version

0.8.7-r12

Describe the Bug

I have some mangas with lots of chapters ( a few k).
For these, it takes a long time to display the chapter list, to start reading a chapter or to transition from a chapter to the next.
Additionally, it sometimes happens that chapters are not properly flagged as read and I also suspect that these manga stall the refresh process (but I haven’t how to investigate).

This is not a network related issue because I have the same symptoms in flight mode with preloaded chapter.
At these times, my iPad grows quite hot, indicating heavy workload.
I tried repairing my database in case but that didn’t change the situation.

I do suspect an indexing strategy with a complexity that does scales well with high number of chapters

Steps to Reproduce

Find a manga with a lot of chapters (you may need to use a 3rd party source for that…)
Bookmark it
Open the bookmark to display the chapter list
Open a chapter (you can download it first to ensure it’s not affected by network conditions)

Anything Else?

I noticed an old, closed issue from 2020 (#6) that also involve manga with a lot of chapters but involved an action with the last page of the chapter.
This may have some connection

update: this seem to be the same issue as #815, which I missed in my initial search. They should be merged but I am not sure about how it should be done and I think I provided additional information worth keeping.