Working code stopped working when reloading rStudio

I have several chunks of code that use pipes and many of them have stopped working when I reloaded rStudio that did not happen before. The following code was working before:

library(dplyr)
df <- data.frame(a = c("A", "B", "A","B" ,"A" ,"B"), b = c(1, 2, 3,4,5,6))
df %>% count(a)

but now it tells me Error in UseMethod("as.quoted") : no applicable method for 'as.quoted' applied to an object of class "function" has to be written as:

count(df$a)

or:

df %>% count(vars="a")

any ideas on what I could have done? rStudio says it's up to date, I'm using R 3.6.1 and I also tried reinstalling dplyr.