Someone great gave me this solution on another forum. Copy the code below and when you print the graph you add the function.
library(tidyverse)
library(plotly)
library(sf)
fixer <- function(gp) {
lapply(1:length(gp$x$data), (m) {
gp$x$data[[m]]$hoveron <<- "fills" # hover on the fill, not line
if(length(gp$x$data[[m]]$text > 1)) {
gp$x$data[[m]]$text <<- gp$x$data[[m]]$text[1] # only one tooltip per county
}
})
gp
}
ggplotly(g, tooltip = "text") %>% fixer() # call the UDF to change tooltips