Thanks for sending the photos.  Fruit tress require that you adopt some form of spray schedule to prevent fungal and insect pest problems.   The gummosis on the fruit is likely due to some type of injury happening to the fruit--- possible feeding from oriental fruit moth or plum curculio egg-laying----you should cut open some of the fruit and look for signs of insects.   The sapcould be due to environmental conditions like excessive water uptake if you see no sign of insects.  Check out this HGIC web page and VA tech home fruit guide- section 3- for spray schedule- https://mgnv.org/wp-content/uploads/2021/03/2021PestManagementGuideHomeGroundsandAnimals.pdf

Let me know if you have any additional questions about what you find or do not find inside the fruit.  

Good luck & Thanks.