If you control the source and the source is excel...
Try removing all the quotes in the file and resaving.
It may be worth opening in an editor (R studio can open as a text file, or notepad) to remove them.
But if the source is extracted from elsewhere, so will recur, then fix in R. Using something like janitor clean names, or a manual renaming or even using colnames with str_replace
colnames(df)<- str_replace("X..", "", colnames(df))
(Where df is the name of your data frame)