Epson 9600 cart needs constantly reprimed

Just wondering if there was any advice on this? The other day, my light magenta stop pulling ink. I tested and cleaned quite a few things before finding a solution to be to pull the cart and reprime it. After the annoyance of having to do this quite a few times during a big job and wasting a bunch or materials and time, I looked closer at the cart and decided to replace it with a new one. That didn’t change anything. Wondering if there’s something else to look at like a damper or something?

Sorry, I’ve been using 9600’s for a long time and do a lot of maintenance, but it’s all been learn as you go so there are many parts I’ve never learned about or had to mess with yet.

Thanks in advance for your time an patience