Different varieties set fruit at different times so you can't compare them with any accuracy. We'd need to know the name of the variety to know if it is a late season variety or not.

Another consideration is the air temps. Blooms will only set fruit within a certain temperature range (see the FAQ here on Blossom Drop) so perhaps this particular plant is experiencing some sort of stress that isn't affecting the others. Or it may just be the variety.

Dave

Here is a link that might be useful: Blossom Drop FAQ