My pubes survived the summer heat here in the deep south, but only set a few pods during the cooler temps of early summer and many more pods when the weather cooled this fall and I'm still waiting on them to ripen. Next season I plan to give them more shade and see how that goes as they definitely like cool weather.
I noticed something very similar with my Rocoto Red this year. Flowers kept appearing, and then falling off. It tried to produce a couple peppers here and there in spring, and I was excited at first... but the two peppers it successfully started growing either rotted or... can't remember what happened to the other, but either way neither one of them made it to maturity.
Then summer hit. All of the plants started growing like wild, including the Rocoto. The Rocoto seemed to produce tons of flowers, but they always fell off the plant a couple days after opening. The summer here seemed to generally be between 80 and 95 degrees Fahrenheit during the day, and while the plant exploded with growth and flowers (probably thanks to the stronger sunlight) it still didn't produce a damn thing. But it sure looked healthy, and was otherwise growing good. I noticed sometime in late spring or early summer many holes appearing in leaves on the plant--so something was targeting it over all the other potted plants on the porch. Whatever it was, after several attempts to catch it/them in action, I tried to stop it with liquid Sevin (hey, if it's not gonna produce anything to eat anyway, and it's not in the ground... why not?). I should mention that the plant received full morning sun, and was shaded the rest of the day, being blocked by a west wall. This was intentional, as I have read about pubescens doing better with some shade and cooler temps if possible. So apparently even just morning sun with, say, 70-75+ degree daytime temperatures still won't help.
Fast forward. The temperatures dropped, quick. So was my patience. It felt like fall was approaching, and I was tempted to give up on that damn plant and throw it out because I have yet to see a single ripened Rocoto on it. And then all of a sudden, I walked outside one day to water the plants and... what the...?! A ripe, red Rocoto. Where the hell did that come from? I have no idea... but it renewed my faith in the plant. Also, I noticed that soon after when the temperatures began kicking the other pepper plants' asses, causing them to slow down growth and even start looking kind of bad, I could've swore that Rocoto plant looked even bigger than the last time I seen it--it must've had a growth spurt somehow, in that cold weather. This was confirmed the following several days and weeks, when flowers didn't just stop dropping off, they actually led to a large burst of peppers finally that have been growing healthy.
Now with a whole bunch of Rocotos on the plant after all this waiting, I decided that it would definitely be one of the plants to overwinter. After all, that one lone pepper leading into the end of summer was unique and tasted good, and the plant was beginning to show promise. Some peppers are ripe or ripening right now as I type, and the Rocoto plant seems to be much easier to overwinter so far than the other plants I'm attempting (Tabasco, Vietnamese Multicolor, NuMex Twilight). There are far fewer aphids on this plant, and when there is an aphid, the branches are big and strong enough that I don't have to worry about damaging the plant by squeezing. I have yet to see a massive colony of aphids like on the other three either (and hopefully it stays that way), and they seem to have fewer places to hide. There seems to be an aphid or two here and there on random stems and leaves, rather than several colonies all over the plant. Also I've noticed very little leaf drop since bring the plant in so far; the Tabasco, similarly, has dropped very few leaves--though that seems to be changing lately.
Now if only I didn't have to defend the plant so long from aphids while waiting for spring to get here again and put the plant outside... I'm actually excited to see how the plant performs next year, assuming it survives.