I have a 5,1 Mac Pro with a Radeon RX580 GPU. Mostly I run Mojave on a GUID 2 Tb EVO 860 SSD in one of the drive bays. It is in an ICY Dock and connects using SATA. It gives no trouble. There are three partitions on the drive.
I have some other SSD's that are formatted APFS, including one that...