Zinc " Interveinal chlorosis, reduction in the size of young leaves having bronze and purple, violet, reddish-brown or brown colouration of the foliage are the prominent deficiency symptoms "
Here’s what I suspected as Mg deficiency a few weeks ago. Treated with epsom salt. And that’s when everything seemed to get worse.Need to check the runoff pH isn't off the clock.
I don't see Mg deficiency. I see a lot of dark P signs. Mg helps P. So could explain Mg helping momentarily.
P can lead to Zn signs. Sometimes (I read) people see the Zn stripes first.
pH would be a good start. Once we have had a proper look