DB replica are missing record, for example for plwikisource
select rev_page from revision where rev_id=782789;
1 row in set (0.00 sec)
MariaDB [plwikisource_p]> select * from page where page_id=291098;
Empty set (0.00 sec)
There is hundred of page like this where the revision table is uptodate but the page table entry doesn't exist.
With a greater page_id than the missing:
select page_title from page where page_id=292652;
So it's not a trouble with replag.