That green tip throws me off the trail for blossom end rot. Its not dead and should be. Still, if it is dying and just not shown in the single picture, you can feed calcium carbonate antacid pills like tums to ensure calcium or use a calcium rich foliar spray. People will use milk, eggshells and other sources also. If it is a fungal attack, daconil is a strong, non organic surface contact broad coverage spray, but if it is virus then no cure only management. My guess is fungal but I have seen sun scald look like that also.

update. same fruit just 24 hrs later. rapid spread. a couple of other plants with fruit same size have same issue this morning. no signs at all on larger fruit. have sprayed with milk last night.

Now the tip looks dead so one might say blossom end rot (BER) is at work, but that is an odd discoloration that I have not yet seen by googling around. Some fungal blights have a broad patch like that but would effect the leaves also. What do they look like?

Hi. Leaves look v.clean, healthy and strong (both sides). Can't find any sign of discolouration or insect damage. Mature fruit look great. So far newer emerging fruit look fine but I've now "lost" 5 fruit like these off 3 plants in 2 days. I've cut open these fruit and damage seems to be limited to skin only in these early stages. Temp has dropped today to 24 degrees after a decent rain. Sprayed with milk solution just in case yesterday.