The drop could be attributable to the hot mic controversy and Yoon's accusation of media manipulation after he came under fire for using vulgar words in private remarks to aides caught on a hot mic during his trip to New York last month, according to Bae Cheol-ho, a senior analyst at Realmeter.
Though the recording of Yoon's remarks was not clear due to noise, many thought that he used foul language while talking about US Congress and US President Joe Biden.
Yoon's office rejected the claim, saying he was referring to South Korea's opposition-controlled National Assembly and did not mention US Congress or Biden.
The poll has a margin of error of plus or minus 2 percentage points at a 95 percent confidence level.
RHM/PR