AFAIK, this event is still "go" (rescheduled from February, I recall). Last I heard a specific date had not been announced; just "this fall." They have a page, but I think it is "Treasure Coast Hamfest"...
Yes, I went to the spring one, very nice, good coffee too; my one minor caveat; the food truck arrived at 10am. LOL. I think there is a typo, should show 2021. https://www.treasurecoasthamfest.com/ NEW DATE TBD FALL 2022 INDIAN RIVER COUNTY FAIRGROUNDS