group_by() and summarise( sum()) functions results NA in some cells

tidyverse
1

I tried using tidyverse/dplyr to create a table from a raw dataframe with 777,546 rows and 23 columns.
When I used group_by () and summarise( sum()) functions, it results NA in some cells. Meanwhile when I try to do pivot in excel, it works perfectly.
Anybody plese tell me what's caused this issue.

2

Read the documentation for the sum() function, most likely there are missing values (NA) in your data frame, if you want to ignore them, you need to set na.rm = TRUE

If you need more specific help, please provide a proper REPRoducible EXample (reprex) illustrating your issue.

3

Solved!
I found out some missing values in the dataframe.
na.rm() function helps me solving this issue.
Thanks