Yeah this is my experience after many more years than I care to remember loitering in gymnasiums filling in time before death.
Seen many people train very hard over the years, and not many have good calves.
I can't recall the study, cause it is along time ago now, and I am braindamaged anyway, but the conclusion was that calves responded to duration of load, or constant loading. IOW, a variety of constant stimulation.
Also, there are IIRC 2 components to calves, gastrocnemius(sp?) and soleus, one of the two underlies the other (can't recall which) and building that up makes the other appear bigger as a natural consequence.
I remember we used to do drop sets, until complete failure, to get a massive pump and exhaust the muscle utterly. The science has probably moved on now, but back then, the school of thought was that to get stubborn muscle groups to grow past a plateau, or genetic set point, the limiting factor was the myofascial sheath, a material similar to car tyre rubber in thickness just about, the idea being massive internal pumps would slowly expand it over time allowing for more growth.
Another one was loading an obscene amount of weight, load the calf machine up with plates, have a friend either side assist you to raise it, but then lower it slowly all by yourself (eccentric contractions) as the most tissue damage occurs when the muscle belly is lengthening under load.
I didn't really need to try to get them to grow though, my calves forearms traps and back used to grow just by looking at a weight, though my chest is as stubborn as a mule, and requires every trick under the sun to coax growth out of it.
In OP's case though I recommend
this