Sequence values change during upgrade

Hi everyone.
I’m upgrading the PostgreSQL version from 12 to 16 using pg_upgrade utility with -k option. After upgrading the database, before starting any application processing, on checking the last value of some sequences, the value has been changed to a value different from the original value. Not all but some of the sequences have modified value. I’ve repeated the upgrade several times and each time the same sequences have changed with the same values. I’ve expected that the upgrade would not interfere with the application data …
This is the upgrade command:

/usr/pgsql-16/bin/pg_upgrade \
—old-datadir=/u01/pgrdb/12/app \
—new-data for=/u01/pgrdb/16/app \
—old-bindir=/usr/pgsql-12/bin \
—new-bindir=/usr/pgsql-16/bin \
-k

Best regards,
Dănuț Soare