Replication - replica falling behind while mysqldump is taken

I am pretty inexperienced with MariaDB, especially replication. However, being 'on call duty' I have an issue with this today. it looks like my replica is falling behind while I am taking a mysqldump of the replica. Is this to be expected behavior or is there an issue with my backup command below? mysqldump --defaults-file=$MYCNF -A --events --routines --master-data=2 | gzip -9 -c > ${BKPFILE} It looks like we are catching up after the dump is finished.