Strange phenomenon

Can anyone tell me if threads are automatically split and locked after a set number of pages?

My forum has a popular thread that reached more than 67 pages. I noticed this morning that it has been split at 67 pages, has been locked, and the rest of the thread is carrying on and has now reached 10 pages.

I asked all my moderators and none of them did this. It was split in the middle of a conversation anyway so seems a strange thing to do.

Then I wondered if threads have a maximum number of pages allowed and then get split by Forumotion, otherwise I cannot account for this happening.

It is not a problem as the first 67 pages are still there, just locked. I just like to have an answer for things

That happens when a thread reaches 990 comments or thereabouts. Confounded me also when it first happened...

this is because no more posts are available at one thread.
forumotion has some limits you know

Oh, thank you guys so much. Yes, the first section has exactly 990 comments.

You will not know this but we have twice been destroyed by a cyber bully and I have had to rebuild the forum twice. My members are vulnerable people with illness and disabilities so you can imagine how vulnerable they feel.

Thank you so much, this will reassure them.

Thanks guys