Your post is not clear.
Please use proper punctuation.
You say TC ports go from ttyS0 to ttyS4, Then you say you tried only ttyS0 to ttyS3 but don't have ttyS4?
Which is it.
Linux default serial driver supports ttyS0 to ttyS3.
Ports above that require a driver or a boot parameter to increase the ttys.
Try the boot code "8250.nr_uarts=8" and see if that solves the problem.