Musing : pivot wider and group_by

library(tidyverse)

I was using pivot_wider and noticed some values were NA for some column and this was not supposed to be the case. I will share a replicated example and what steps I used

Variable <- LETTERS[1:5]
Value <- rep(10:29)
Year <- rep(2010:2014)
df <- data.frame(c(Year, Year, Year, Year), c(Variable,Variable, Variable, Variable), Value)
colnames(df) <- c("Year", "Variable", "Value")
df %>% 
  pivot_wider(names_from = Variable, values_from = Value, values_fn = list(Value=mean)) ->df1
df %>% 
  group_by(Year, Variable) %>% 
   pivot_wider(names_from = Variable, values_from = Value, values_fn = list(Value=mean))
## # A tibble: 5 x 6
## # Groups:   Year [5]
##    Year     A     B     C     D     E
##   <int> <dbl> <dbl> <dbl> <dbl> <dbl>
## 1  2010  17.5  NA    NA    NA    NA  
## 2  2011  NA    18.5  NA    NA    NA  
## 3  2012  NA    NA    19.5  NA    NA  
## 4  2013  NA    NA    NA    20.5  NA  
## 5  2014  NA    NA    NA    NA    21.5