Parallel redo is started for database

Hello

I have a sql 2017 Standard

Several times this warning apears in logs:

SPID52 Parallel redo is started for database xxxx with worker pool size (6)
and immediately arises the other one
SPID52 Parallel redo is shuting down for database xxxx with worker pool size (6)

Those messages arise when backups are iniciated (maintenance plan)

Can I have some help?

Thanks