In the code below, I test whether there are any common Dates between wti and pa and I find there are not. I then change two dates in wti to match dates in pa and do a merge. The merge results in a data frame with two rows, as expected. Your full data set may well have some matching dates and using only a subset of the data may have caused the apparent lack of matches. However, you should check and see if that is the cause of your merge problems.
wti <- structure(list(ï..Date = c("1/3/2022", "12/1/2021", "11/1/2021",
"10/1/2021", "9/1/2021", "8/2/2021", "7/6/2021", "6/1/2021",
"5/3/2021", "4/1/2021", "3/1/2021", "2/3/2021", "1/21/2021",
"1/4/2021", "12/1/2020", "11/5/2020", "10/16/2020", "9/30/2020",
"9/14/2020", "8/31/2020"),
End.Date = c("1/16/2022", "12/16/2021",
"11/16/2021", "10/19/2021", "9/17/2021", "8/17/2021", "7/21/2021",
"6/18/2021", "5/18/2021", "4/21/2021", "3/15/2021", "2/18/2021",
"2/2/2021", "1/15/2021", "12/17/2020", "11/19/2020", "10/27/2020",
"10/15/2020", "9/28/2020", "9/13/2020"),
Approving = c(40L, 43L, 42L, 42L, 43L, 49L, 50L, 56L, 54L, 57L, 54L, 56L, 57L, 34L, 39L, 43L, 46L, 43L, 46L, 42L),
Disapproving = c(56L, 51L, 55L, 52L,
55L, 48L, 45L, 42L, 40L, 40L, 42L, 40L, 37L, 62L, 57L, 55L, 52L,
55L, 52L, 56L),
Unsure.NoData = c(4L, 6L, 3L, 6L, 2L, 3L, 5L,
2L, 6L, 3L, 4L, 4L, 6L, 4L, 4L, 2L, 2L, 2L, 2L, 2L),
Date = c("1/3/2022", "12/1/2021", "11/1/2021", "10/1/2021", "9/1/2021", "8/2/2021",
"7/6/2021", "6/1/2021", "5/3/2021", "4/1/2021", "3/1/2021", "2/3/2021",
"1/21/2021", "1/4/2021", "12/1/2020", "11/5/2020", "10/16/2020",
"9/30/2020", "9/14/2020", "8/31/2020")),
row.names = c(NA, 20L
), class = "data.frame")
pa <- structure(list(ï..Date = c("3/6/2022", "2/27/2022", "2/20/2022",
"2/13/2022", "2/6/2022", "1/30/2022", "1/23/2022", "1/16/2022",
"1/9/2022", "1/2/2022", "12/26/2021", "12/19/2021", "12/12/2021",
"12/5/2021", "11/28/2021", "11/21/2021", "11/14/2021", "11/7/2021",
"10/31/2021", "10/24/2021"),
Price = c(107.38, 115.68, 91.59,
91.07, 93.1, 92.31, 86.82, 85.14, 83.82, 78.9, 75.21, 73.79,
70.86, 71.67, 66.26, 68.15, 76.1, 80.79, 81.27, 83.57),
Open = c(122.25, 94.99, 91.75, 93.91, 91.82, 87.45, 84.91, 84.32, 78.88, 75.69,
73.38, 70.07, 72.04, 67.02, 69.23, 75.75, 80.66, 81.13, 83.36,
83.98),
High = c(130.33, 116.57, 100.54, 95.82, 94.66, 93.17, 88.84, 87.91, 84.45, 80.47, 77.44, 73.95, 73, 73.34, 72.93, 79.23,
81.81, 84.97, 84.88, 85.41),
Low = c(103.87, 94.43, 90.06, 89.03, 88.41, 86.34, 81.9, 82.78, 77.83, 74.27, 72.57, 66.04, 69.39,
66.72, 62.43, 67.4, 75.37, 79.78, 78.25, 80.58),
Vol. = c("-", "2.43M", "1.35M", "1.52M", "1.90M", "1.66M", "1.91M", "307.18K", "1.66M", "1.57M", "1.03M", "972.44K", "1.28M", "2.15M", "3.12M", "2.15M", "958.31K", "2.32M", "2.62M", "2.57M"),
Change.. = c("-7.17%", "26.30%", "0.57%", "-2.18%", "0.86%", "6.32%", "1.97%", "1.57%", "6.24%", "4.91%", "1.92%", "4.13%", "-1.13%", "8.16%", "-2.77%", "-10.45%", "-5.81%", "-0.59%", "-2.75%", "-0.23%"),
Date = c("3/6/2022", "2/27/2022", "2/20/2022", "2/13/2022", "2/6/2022", "1/30/2022", "1/23/2022", "1/16/2022", "1/9/2022", "1/2/2022", "12/26/2021", "12/19/2021", "12/12/2021", "12/5/2021", "11/28/2021", "11/21/2021", "11/14/2021", "11/7/2021", "10/31/2021", "10/24/2021")),
row.names = c(NA, 20L), class = "data.frame")
#Check if any dates in wti are also in pa
any(wti$Date %in% pa$Date)
#> [1] FALSE
#Confirm by inspection that there are no matches.
wti$Date
#> [1] "1/3/2022" "12/1/2021" "11/1/2021" "10/1/2021" "9/1/2021"
#> [6] "8/2/2021" "7/6/2021" "6/1/2021" "5/3/2021" "4/1/2021"
#> [11] "3/1/2021" "2/3/2021" "1/21/2021" "1/4/2021" "12/1/2020"
#> [16] "11/5/2020" "10/16/2020" "9/30/2020" "9/14/2020" "8/31/2020"
pa$Date
#> [1] "3/6/2022" "2/27/2022" "2/20/2022" "2/13/2022" "2/6/2022"
#> [6] "1/30/2022" "1/23/2022" "1/16/2022" "1/9/2022" "1/2/2022"
#> [11] "12/26/2021" "12/19/2021" "12/12/2021" "12/5/2021" "11/28/2021"
#> [16] "11/21/2021" "11/14/2021" "11/7/2021" "10/31/2021" "10/24/2021"
wti[1,"Date"] <- "1/2/2022"
wti[4,"Date"] <- "10/31/2021"
MergedData <- merge(wti,pa,by="Date")
MergedData
#> Date ï..Date.x End.Date Approving Disapproving Unsure.NoData
#> 1 1/2/2022 1/3/2022 1/16/2022 40 56 4
#> 2 10/31/2021 10/1/2021 10/19/2021 42 52 6
#> ï..Date.y Price Open High Low Vol. Change..
#> 1 1/2/2022 78.90 75.69 80.47 74.27 1.57M 4.91%
#> 2 10/31/2021 81.27 83.36 84.88 78.25 2.62M -2.75%
Created on 2022-05-01 by the reprex package (v2.0.1)