It is now October 2020 and I have the problem of a Humax hard disk failing. In fact this is the second one that has failed. I am feed up with Seagate Pipeline disks. Also as they are not readily available I'm wondering if those that are available are just refurbs being pushed onto the market. Anyway I decided to try something different and went with a 2Tb WD purple disk, WD10EZEX. These are for use in surveillance systems and designed for 24 hour running. My only concern was the playback speed, but the disk has now been in use for nearly a month and it is working fine.
If I have any problems with it I will post the information here.