I have had numerous Cache pool issues, and in 1 month of Unraid operation have yet to keep the pool working with it continuously going to read only mode. Currently i have 5 drives that were a part of the pool and a 6th i removed because it was having issues. But, the read/write issues i had are the same numerous others have had. 

I have (2) 500GB SSD's and (4) 1TB SSD's i would like to run in this pool. I tried swapping HD cables and that didnt help, but i bought all new ones and will try again later today. I ran

 

btrfs dev stats -z /mnt/cache

and after waiting a bit got 

[/dev/sdw1].write_io_errs    0
[/dev/sdw1].read_io_errs     0
[/dev/sdw1].flush_io_errs    0
[/dev/sdw1].corruption_errs  0
[/dev/sdw1].generation_errs  0
[/dev/sdt1].write_io_errs    0
[/dev/sdt1].read_io_errs     0
[/dev/sdt1].flush_io_errs    0
[/dev/sdt1].corruption_errs  0
[/dev/sdt1].generation_errs  0
[/dev/sdu1].write_io_errs    0
[/dev/sdu1].read_io_errs     0
[/dev/sdu1].flush_io_errs    0
[/dev/sdu1].corruption_errs  0
[/dev/sdu1].generation_errs  0
[/dev/sdv1].write_io_errs    815880612
[/dev/sdv1].read_io_errs     720904356
[/dev/sdv1].flush_io_errs    6496
[/dev/sdv1].corruption_errs  0
[/dev/sdv1].generation_errs  0
[/dev/sdy1].write_io_errs    9060180
[/dev/sdy1].read_io_errs     8082656
[/dev/sdy1].flush_io_errs    51
[/dev/sdy1].corruption_errs  0
[/dev/sdy1].generation_errs  0

The Both sdv1 and sdy1 are new SSD's, and sdw1 got a notification on boot that says Cache pool BTRFS missing device(s). Even though on drive status in main page it shows green. Any idea what my issue could be?

Those write/read errors are a hardware problem, usually a cable problem with SSDs, but could also be controller related, you should post the diags.