Versacamm (always black) head deflecting

I am having to replace black/blue head over and over, almost yearly on my Versacamm SP-300v. I don't print a huge amount on this printer. Maybe a few hours a week. After replacing this head, printer soon develops exactly the same problem which gets worse over time. Absolutely no head-strikes (as you can see blue head is just fine), never letting it dry out. The machine is always plugged in and gets ink circulated by powering up automatically all the time. Why is it that black is always doing this? Could it be something else that is causing it? This is the third or fourth time I have replaced this printhead developing this problem for no apparent reason. I did try soaking the printhead for a couple of hours and can try overnight as well, but this didn't help in the past. I cleaned everything, including wipe blades (which are new), and last time everything that could affect these heads were also replaced: damper, wiper heads, cap tops. The printer always uses OEM inks. What could be causing it?

 

Thanks, Jim. So you think if I soak it repeatedly now, the nozzles may recover or is it too late for this head?