I have a problem with my greenhouse tomatoes.
The larger ones, Purple Ukraine, Chocolate Cherokee, Burpee's Jubilee and Greek have all been affected. At first I thought it was blossom end rot, but it doesn't look quite right for that.
The plants are otherwise healthy.
Smaller types, Black Cherry, White Cherry, Baby Gazzi, Sweet Aperitif all unaffected.
All types in same compost. Same varieties in the polytunnel at the allotment all unaffected.
Watered regularly.
Here is a picture of 2 affected fruits.
Any suggestions as to what it is.