Some varieties require large spaces in order to do well and might not be as suitable for container as others. I don't grow this variety, and perhaps I have it under a different name.
I had Sicilian variety that did nothing for over four years. Then suddenly it is loaded with fruit.
Here's what I believe happened. Some varieties take longer to produce than others, but the key is a strong root system. Without it, I'm getting mediocre results from many trees. A few figs here and there of varying quality.
My conclusion is that the size of container does matter a lot. The deeper the container the better. This goes hand in hand with the quality of soil and soil contents.
So the five gallon containers do work, but they just keep the plants going, but observation tells me that in order to get much better results, the height of container should be at least two to three times the height of the five gallon pot.
I'm no expert, but the results that I'm getting confirm this. Even when a tree goes in ground a period of adjustment could last several years before it finally takes off.
I have several varieties that are behaving like your Rasberry Latte, among them are Noir de Caromb, Hative d'Argenteuil, Etc...
Unless I can provide the right medium for my figs, at this point I'd rather have fewer trees in the right size pots that make them more productive rather than a hundred that are what I call idle in the wrong size pot.