It looks like your expander is reporting disk partitions incorrectly, or Linux is confused about partiutions. For example:
[/dev/sdq]
ACTION="add"
DEVLINKS="/dev/disk/by-id/ata-HUH728080ALE601_VJGU11NX-part1 /dev/disk/by-id/wwn-0x5000cca261cb613b-part1 /dev/disk/by-label/_VJGU11NX /dev/disk/by-partuuid/ba941532-6339-466e-b184-207d8dca3dc7 /dev/disk/by-path/pci-0000:00:10.0-sas-exp0x50030480004c4cbf-phy26-lun-0-part1 /dev/disk/by-uuid/3d1454c4-d04d-40f4-90ef-07979c3a2eb6"
DEVNAME="/dev/sdcq1"
DEVPATH="/devices/pci0000:00/0000:00:10.0/host4/port-4:0/expander-4:0/port-4:0:277/end_device-4:0:277/target4:0:315/4:0:315:0/block/sdcq/sdcq1"
DEVTYPE="partition"
Is reporting partition '/dev/sdcq1' on disk '/dev/sdq'.
[/dev/sdcb]
ACTION="add"
DEVLINKS="/dev/disk/by-id/ata-HUH728080ALE601_VJGU11NX-part1 /dev/disk/by-id/wwn-0x5000cca261cb613b-part1 /dev/disk/by-label/_VJGU11NX /dev/disk/by-partuuid/ba941532-6339-466e-b184-207d8dca3dc7 /dev/disk/by-path/pci-0000:00:10.0-sas-exp0x50030480004c4cbf-phy26-lun-0-part1 /dev/disk/by-uuid/3d1454c4-d04d-40f4-90ef-07979c3a2eb6"
DEVNAME="/dev/sdcq1"
Is reporting partition '/dev/sdcq1' on disk '/dev/sdcb'.
Try downgrading to a version of Unraid that you think may have worked. Also try Unraid 7.0 beta and see if that works.
EDIT: So I found this situation is a bug in UD, but not sure how it could cause your issue.