Hmm, this is probably useless info but if this were an HP I'd say it looks like the head chamber is running out of ink (basically full of air), so either some kind of ink delivery issue or the usual air leakage into the line/head that occurs over time.
But I don't know if any of that is relevant to the Epson 9570. But a large section of head nozzles repeatedly going blank after a few mins of printing looks to me like no ink in head.
The way that test patch is split in two -- one half ok the other almost blank -- makes me wonder if the head uses some kind of dual-chamber design.
Sorry that's no help with fixing it tho. Hopefully you don't need a new head, I hear the costs are crazyyy for Epson heads.
