RN316 x-raid vertical expansion not reaching expected capacity

OS 6-10-4

Raid 5

Have upgraded 2 disks to 8Tb but X-raid is not using the disk capacity

Disk /dev/sda: 5860533168 sectors, 2.7 TiB
Model: WDC WD3003FZEX-0
Sector size (logical/physical): 512/4096 bytes
Disk identifier (GUID): 2D669D56-5D3B-4700-AF41-2C2E1FD0703A
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 5860533134
Partitions will be aligned on 64-sector boundaries
Total free space is 45 sectors (22.5 KiB)

Number Start (sector) End (sector) Size Code Name
1 64 8388671 4.0 GiB FD00
2 8388672 9437247 512.0 MiB FD00
3 9437248 1953525119 927.0 GiB FD00
4 1953525120 5860533119 1.8 TiB FD00
Disk /dev/sdb: 15628053168 sectors, 7.3 TiB
Model: WDC WD80EFAX-68K
Sector size (logical/physical): 512/4096 bytes
Disk identifier (GUID): A048CB56-0F2B-4D0B-96D5-1B3F5C07E5C7
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 15628053134
Partitions will be aligned on 64-sector boundaries
Total free space is 7814016045 sectors (3.6 TiB)

Number Start (sector) End (sector) Size Code Name
1 64 8388671 4.0 GiB FD00
2 8388672 9437247 512.0 MiB FD00
3 9437248 1953525119 927.0 GiB FD00
4 1953525120 5860533119 1.8 TiB FD00
5 5860533120 7814037119 931.5 GiB FD00
Disk /dev/sdc: 15628053168 sectors, 7.3 TiB
Model: WDC WD80EFAX-68K
Sector size (logical/physical): 512/4096 bytes
Disk identifier (GUID): D431626D-1023-4469-B4D7-94AEBA3C87F2
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 15628053134
Partitions will be aligned on 64-sector boundaries
Total free space is 7814016045 sectors (3.6 TiB)

Number Start (sector) End (sector) Size Code Name
1 64 8388671 4.0 GiB FD00
2 8388672 9437247 512.0 MiB FD00
3 9437248 1953525119 927.0 GiB FD00
4 1953525120 3907029119 931.5 GiB FD00
5 3907029120 7814037119 1.8 TiB FD00
Disk /dev/sdd: 7814037168 sectors, 3.6 TiB
Model: WDC WD40EZRX-00S
Sector size (logical/physical): 512/4096 bytes
Disk identifier (GUID): 1CD816CD-F31C-48E8-A480-7FBD3AD57AB3
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 7814037134
Partitions will be aligned on 64-sector boundaries
Total free space is 45 sectors (22.5 KiB)

Number Start (sector) End (sector) Size Code Name
1 64 8388671 4.0 GiB FD00
2 8388672 9437247 512.0 MiB FD00
3 9437248 1953525119 927.0 GiB FD00
4 1953525120 5860533119 1.8 TiB FD00
5 5860533120 7814037119 931.5 GiB FD00
Disk /dev/sde: 7814037168 sectors, 3.6 TiB
Model: WDC WD40EZRX-00S
Sector size (logical/physical): 512/4096 bytes
Disk identifier (GUID): 5AD5549D-9FC8-4920-887F-140433642546
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 7814037134
Partitions will be aligned on 64-sector boundaries
Total free space is 45 sectors (22.5 KiB)

Number Start (sector) End (sector) Size Code Name
1 64 8388671 4.0 GiB FD00
2 8388672 9437247 512.0 MiB FD00
3 9437248 1953525119 927.0 GiB FD00
4 1953525120 5860533119 1.8 TiB FD00
5 5860533120 7814037119 931.5 GiB FD00
Disk /dev/sdf: 5860533168 sectors, 2.7 TiB
Model: WDC WD30EZRX-19D
Sector size (logical/physical): 512/4096 bytes
Disk identifier (GUID): 7059BCC2-3EF0-4319-9374-5A8D7DA163EA
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 5860533134
Partitions will be aligned on 64-sector boundaries
Total free space is 45 sectors (22.5 KiB)

Number Start (sector) End (sector) Size Code Name
1 64 8388671 4.0 GiB FD00
2 8388672 9437247 512.0 MiB FD00
3 9437248 1953525119 927.0 GiB FD00
4 1953525120 5860533119 1.8 TiB FD00

How can I get system to use extra 3.6Tb?

Can in be done without factory reset?

What are RN316 limits?