Use of the keyword directory () function. It does not perform a correct count with R

I am using the pepa function to extract the paragraphs with the word "Artificial Intelligence" in pdf documents. However, I do not extract all the paragraphs with those words. I missed a lot less. It does not get to extract those from the ends of the document.

library(textreadr)
library(tidyverse)
library(pdfsearch)

dirct <- directory_path
result <- keyword_directory(dirct, keyword = 'Artificial Intelligence', split_pdf = TRUE, surround_lines = 0, full_names = TRUE)

For example, in this file:
https://www.telefonica.com/documents/153952/13347920/2019-Telefonica-Consolidated-Management-Report.pdf/0a9c8382-c9ff-ba52-1d5b-e431a7efab3f

I only get 22 mentions, however there are about 40 mentions of this keyword (Artificial Intelligence)

For what is this?

data_frame <- read.csv2(...)

data_frame <- mutate(data_frame, columx = 0)

data_frame$columx[grepl("artificial intelligence", data_frame$columx, ignore.case = TRUE)] <- 1