probably just a temporary(and inscrutable)phase your tree is going through and hopefully will bounce back. I see a fair amount of fruits on your hj, but i agree-- not as densely fruiting as typical hj’s, even those in more northerly latitudes where trees don’t get as much sun as yours.
not sure if you had plenty of rain, as too much water dilutes/leaches the soil which may affect fruiting,and perhaps also influenced by the rootstock. Unlike conventional fruits, nurseries use random seedlings/suckers for jujus, so you might want to take some hj stems and graft to your abundantly producing chico to see if there will be a difference in production. Jujus may be popular, but still quite unknown, at least here in usa. Being easy to grow here with hardly any input other than soil, water, and sun, it is easy to overlook what we probably should oversee.
so speaking of rootstock, i admit it sounds intrusive, but am compelled to volun-tell @BobVance, @Chills, and @tonyOmahaz5 to consider propagating suckers from rootstock of their most productive juju trees which seem to support fruit production in their respective locations. Those bloodlines may just be the ticket to solve the borderline or scarce production of jujus in cold/wet regions of usa. It is virtually impossible to control rain, humidity, wet soils, winter cold, amount of sunlight during growing season, etc, and impossible to change the genetics of scionwood, but those issues may be ameliorated by using rootstock which seem to do very well planted outside of tri-state AZ-CA-NV.
probably good to sort out the other variable to which we graft the scions on. So everyone here please keep everybody posted with both good/bad findings, am confident our e-group will figure things out over the years