I mean are any of the dies on any of the cobs out? If so, it would take a higher voltage drop to get the same current through the diodes in the damaged cob. That higher drop may go over the max voltage of the driver, and thus current is significantly throttled.
Astring of 3? in parallel or the other way. Might need a refresher course on stringing.
If I get it right, you're currently running 4 3590s in series on a single HLG185H-C700B. That driver has minimal Vf = 143V so you can safely run any 3 3590s in series. This way you can find out if the troubles are caused by one of the COBs perhaps. You'll also find out what Vf do your COBs need to achieve 700mA. Perhaps they're CXAs and need a higher voltage?
So when run in parallel do all led's only draw 1/4? Got my HYPER fan hooked up and it is nice.
Think of it like plumbing. If you have 4 pipe segments each with 1-way flow restriction valves (diodes), if you put them in parallel, the current will be divided between the 4 pipes, although not equally. If you put them in series, the same current will go through all 4 pieces of pipe.
No one ever compared it to plumbing like that to me, that works for me.