I have 2 csv files and opened them in R. if I print the first few lines, they would look like the following:

> head(file1)
   X         target_id gene_name
1  1 ENSG00000223972.4   DDX11L1
2  2 ENST00000456328.2   DDX11L1
3  6 ENST00000515242.2   DDX11L1
4 10 ENST00000518655.2   DDX11L1
5 15 ENST00000450305.2   DDX11L1
6 22 ENSG00000227232.4    WASH7P
> 
> 
> head(file2)
          target_id length eff_length est_counts tpm
1 ENST00000632684.1     12         13          0   0
2 ENST00000434970.2      9         10          0   0
3 ENST00000448914.1     13          1          0   0
4 ENST00000415118.1      8          9          0   0
5 ENST00000631435.1     12         13          0   0
6 ENST00000390567.1     20          8          0   0

I am trying to merge (join) them and create something like the following:

target_id   gene_name length eff_length est_counts tpm
ENSG00000000003.10  TSPAN6  0   7   7   2
ENSG00000000005.5   TNMD    1   1   8   3
ENSG00000000419.8   DPM1    2   5   1   4
ENSG00000000457.9   SCYL3   1   6   8   5
ENSG00000000460.12  C1orf112    5   7   4   3
ENSG00000000938.8   FGR 3   8   0   0

but what I am getting looks like this:

target_id       X gene_name length eff_length est_counts tpm
ENSG00000000003.10 2573196    TSPAN6     NA         NA         NA  NA
ENSG00000000005.5 2573172      TNMD     NA         NA         NA  NA
ENSG00000000419.8 2430409      DPM1     NA         NA         NA  NA
ENSG00000000457.9  180498     SCYL3     NA         NA         NA  NA
ENSG00000000460.12  179894  C1orf112     NA         NA         NA  NA
ENSG00000000938.8   45152       FGR     NA         NA         NA  NA

the code I am using in R is:

merged_data <- merge(file1, file2, by = "target_id", all.x = TRUE)

do you know how to fix it?