The test innodb.innodb_wl6326 that was disabled in 10.4 due to failures caused by MDEV-21535 is failing on 10.5 due to another reason: the removal of the MLOG_COMP_END_COPY_CREATED operations in MDEV-12353 caused PAGE_LAST_INSERT to be set to something nonzero by the function page_copy_rec_list_end().

This in turn would cause btr_page_get_split_rec_to_right() to behave differently: we would not attempt to split the page at all, but simply insert the new record into the new, empty, right leaf page.

Even though the change reduced the sizes of some tables, it is better to aim for balanced trees.