You can freeze dragon fruit but if you freeze dragon fruit it will change the texture and taste so frozen dragon fruit is not as good tasting when eaten directly.
But if you do freeze dragon fruit it's best to use frozen dragon fruit for pureed foods where you won't really notice the texture or taste change.
Frozen dragon fruit makes for great smoothies when blended up and you can even blend the frozen dragon fruit up and make baby food out of them.
I've frozen dragon fruits and then pureed them and then fed them to my kids when they were babies and could eat baby food.
They loved the pureed dragon fruit better than any other store bought baby food.
My kids when they were babies were very happy to get the dragon fruit fed to them and wanted more and more.
I love dragon fruit as well and would eat some pureed dragon fruit myself.