In reply to this post:-
https://community.spiceworks.com/topic/1957686-non-certified-dell-drives-compatible

And Continuing from this post:-
http://www.mutface.com/index.php/2019/10/dell-perc-h700-h710-clear-foreign-status-on-raid-array/

DELL tries to discourage people from using non-dell branded harddrives but actually I have a DELL T310 running RAID 10 on all seagate harddrives with no problem. Recently I had a R520 with 8 DELL drives and one of them got degraded; my main supplier said they needed 2-3 weeks to order a drive so having gone online and found a lot of resources on dell.com discouraging people from using non-dell drives I decided to delve deeper and found that actually DELL drives are in fact Seagate drives with a different label.

In the end I found that the “FOREIGN” drive in my previous article became FOREIGN because it was degraded so half way through the rebuild it showed up as degraded. Because we didn’t have time to order a DELL drive we just slotted in a Seagate SATA 3.5″ drive and the RAID was able to rebuild without problems. Please see below screenshot of the final result.