I’m not too sure about varietals of any of the trees. One mango I know is called a lemon meringue mango, and as you might guess is very citrusy. It’s much smaller and paler than the usual Caribbean mangoes at the supermarket. Likewise not sure about either avocado. One is what’s colloquially called a Florida avocado. It’s huge - like bigger than a softball - with a smooth, bright green skin. The flesh is a bit watery, to the point where I use cheesecloth to wring it out if making guac. Milder than a haas as well. The other variety is really interesting. It ripens on the vine until it is dark purple or almost black, like an eggplant. This one is delicious and slightly floral. I haven’t seen any fruits on either tree again this year, so something is definitely up. An arborist was over a few years ago to do some pruning and didn’t mention anything problematic about either, so it will likely take some research to figure out. I’m not aware of other avocado trees in the neighborhood, but certainly one possibility is that they’ve lost their pollinators.