In my experience with Epson printers & compatible inks (the only ones I've used), stripes mean the heads need cleaning.
This will involve the use of more ink, so make sure you've enough to replace the carts as needed. You might need to perform the cleaning procedure several times.
One of the problems with compatible inks is that they'll often show the level in the cart as sufficient, but the printer is "unwilling" to use it - you have to accept the loss of what's left in the cart & balance it against the cost of a new one - I paid 61p per cart for my last order & am very happy with them so far.