wt_verify_disagg_database_size is invoked from wiredtiger_open (under verify_metadata=true) before any post-open reconfigure has run. The in-memory conn->disaggregated_storage.database_size is populated only by checkpoint pickup (disagg_finalize_checkpoint_meta), so a follower that opens without disaggregated.checkpoint_meta in its initial config sees database_size == 0 while local metadata still carries the prior run's .wt_stable checkpoints. The verify then trips a spurious mismatch, most visibly in test/format, which supplies checkpoint_meta via reconfigure after open, not at open.