Conditional str_remove based on data frame column - r

Question

I have a dataframe (pasted below), in which I am trying to set to blank the value of one column based on the value of another column. The idea is that if X6 equals Nbre CV or if X6equals Nbre BVD then I want X6for that row to be blank.
Unfortunately using the following code the entire X6 column turns to NA or missing.
extractstack <- extractstack %>%
mutate(across(everything(), as.character) %>%
mutate(X6 = if_else(X6 == `Nbre CV`, str_remove(X6, `Nbre CV`), X6)) %>%
mutate(X6 = if_else(X6 == `Nbre CV`, str_remove(X6, `Nbre BVD`), X6)))
structure(list(X1 = c("", "", "40", "", "", "41", "", "", "42",
"", "", "43", "", "", "44", ""), X2 = c("", "", "EP. KAPALA",
"", "", "INST. MOTULE", "", "", "CABANE BABOA", "", "", "CABANE BANANGI",
"", "", "E.P.BINZI", ""), X3 = c("", "", "MOBATI-BOYELE", "",
"", "MOBATI-BOYELE", "", "", "MOBATI-BOYELE", "", "", "AVURU-GATANGA",
"", "", "AVURU-GATANGA", ""), X4 = c("", "", "BOGBASA", "", "",
"BOSOBEA", "", "", "BOSOBEA", "", "", "BANANGI", "", "", "GURUZA",
""), X5 = c("", "", "", "", "", "MOBENGE", "", "", "BABOA", "",
"", "DIFONGO", "", "", "DULIA", ""), X6 = c("", "", "BOGBASA",
"", "", "", "1", "", "", "1", "", "", "1", "", "", "1"), X7 = c("1",
"", "", "1", "", "", "4", "", "", "1", "", "", "1", "", "", "5"
), X8 = c("2", "", "", "2", "", "", "510 110", "", "", "510 111",
"", "", "510 112", "", "", "510 113"), X9 = c("510 108", "",
"", "510 109", "", "", "A - D", "", "", "A", "", "", "A", "",
"", "A - E"), page = c("4", "4", "4", "4", "5", "5", "5", "5",
"5", "5", "5", "5", "5", "5", "5", "5"), Plage = c("A - B", NA,
NA, "A - B", NA, NA, "A - D", NA, NA, "A", NA, NA, "A", NA, NA,
"A - E"), `Code SV` = c("510 108", NA, NA, "510 109", NA, NA,
"510 110", NA, NA, "510 111", NA, NA, "510 112", NA, NA, "510 113"
), `Nbre BVD` = c("2", NA, NA, "2", NA, NA, "4", NA, NA, "1",
NA, NA, "1", NA, NA, "5"), `Nbre CV` = c("1", NA, NA, "1", NA,
NA, "1", NA, NA, "1", NA, NA, "1", NA, NA, "1")), class = "data.frame", row.names = c(NA,
-16L))

Answer 1

That's basically Chris Ruehlemann's answer (I don't know why he removed it, I would remove this one for the original one):
library(dplyr)
extractstack %>%
mutate(across(everything(), as.character),
X6 = coalesce(ifelse(X6 == `Nbre BVD` | X6 == `Nbre CV`, "", X6), X6))
compares X6 with the columns Nbre BVD and Nbre CV. If there is matching content, X6 will be changed to an empty string "", else X6 stays unchanged. But for your given data, this code doesn't replace anything, since there are simply no matches in X6 with Nbre BVD and Nbre CV besides NA-values.