It would be almost impossible to diagnose this from a picture. Probably not much easier to diagnose in person. That being said, and with the proviso that I am no expert in drastic pruning (aka pugging), looks to me like the tree just decided to put its energy into the other sprouted branches from the prune point. I don't see any disease (it would be hard to see it even if it was there). I think the wilted brances just lost their connectivity with the water/nutrient flow in the trunk of the tree. Beyond that, I am not sure what to tell you. If that is all it is you will have no further problems and the tree will push its growing energy into the remaining growths. If it something caused by disease, then it is either bacterial, viral or fungal. If fungal, the fungicide will help, but a systemic might be more effective. If viral or bacterial, not much can be done and tree will either grow itself out of it or it will slowly decline. As far as it spreading if there is a disease process ongoing, that would likely happen with you using unsterilized cutting tools on other plants or by insects, probably not from mere proximity. Good luck!

Harry

So sorry about the wilting leaves Invar...I wish I can be of help but I've never encountered this with any of my mango trees. Hopefully, like Harry mentioned...maybe the tree will just continue to push the energy to the remaining new growths and you won't see any more problems. Best of luck!

what you are witnessing is normal of new growth IMO and not indicative of any decline.

heres some new growth on my st maui this morning

There appears to be something wrong with the leaves on the left of the 2nd Southern Blush picture. Could be water stress but that usually affects the whole plant.

The Lancetilla looks fine other than that black mark on the stem.

Thank you all for your input. I suspected it might be the plants editing itself but its great to hear that it could be just a 'normal' process.
I did forget to water it over one of the long weekends and the soil nearly dried out, so perhaps its that. Thanks again.

I have another question: Once a twig dies off, does that mean that node will never produce another growth again?

BTW, Mango-Kush, Thanks for posting your St Maui pic. Have you tasted it? I was thinking of getting one.

The second pic does look like water stress, didn't notice it at first. The new growth being thin pale and light at first is normal

I am starting to have the same issue with my mango. Did your tree recover?