There are many many posts here about recording to powered and unpowered UDB lined HDDs and SSDs.
Is there a definitive answer before a chase us a full refund from John Lewis?
I have 2 Samsung TVs. 1 from June 2015 and 1 from April 2018. Neither have ever been more than 50% on scheduled recording - and having lost some great TV over Xmas Samsung's time is up. Its either a new LG set, or a Humax Arua PVR.
Note the newer one wont record whats on the TV in front of me to my powered HDD now - despite having done so begrudgingly for some 25Gb of TV.
Ive been on the phone with Samsung support and there is seemingly nothing they can do!