In my case, I had one id containing two games/sessions, as shown by different dates in my column timeStamp which is of char data type in the raw data.

The example below shows how I differenciated the two IDs. Let’s say the second player played the game on March 14, 2024 and I want to change it’s id to "2".

df <- raw %>%
  dplyr::mutate(id = ifelse((grepl("^20240314.*$", timeStamp, ignore.case = TRUE) # if timeStamp begins by "20240314"
                              & id == "1"), # and id is "1"
                              "2", # change id to "2"
                              id)) # else keep it as is

Regex tips:

^ marks the begining of the string, .* marks anything (like the * in C), $ marks the end of the string