MISCONF Redis is configured to save RDB snapshots

Everything works as normal but after about 3 days or so the error of “There has been a critical error on this website” comes up. This stops me logging into the wordpress dashboard.

The error in the logs comes up below:

Predis\Response\ServerException: MISCONF Redis is configured to save RDB snapshots, but it is currently not able to persist on disk. Commands that may modify the data set are disabled, because this instance is configured to report errors during writes if RDB snapshotting fails (stop-writes-on-bgsave-error option). Please check the Redis logs for details about the RDB error.

Under WHM, Terminal the following commands I have also checked the status also to shows redis not running. When I restart redis using systemctl restart redis I can access the wordpress dashboard. The commands are below.

To check with the Redis status use the following command: 
systemctl status redis

To restart the redis use the following command:
systemctl restart redis

Are you able to advise what’s causing redis to stop and what can be done to prevent this reoccurring as this is the 2nd time this has happened?