The song was meant to salute the healthcare workers at the frontline of the coronavirus pandemic, but it ended up highlighting the political tensions between China and Taiwan.
Taiwanese singer Jolin Tsai, 39, and Hong Kong singer Eason Chan, 45, collaborated for the first time on the English song, Fight As One. They recorded the song in their respective studios.
The music video for the song, which was uploaded on YouTube last Friday (April 3), was initially well received, and both singers promoted the song on their social-media accounts.
However, some netizens were quick to find fault with a photo montage in the video showing children around the world drawing flags of China or writing words thanking China.
Some Taiwanese netizens also asked why photos of healthcare workers in the video did not include those from Taiwan, while others pointed out that the video was produced in collaboration with China's Yunnan Television.
Fans of the two award-winning singers defended them, noting that they recorded the song in different studios and the montage was probably put in by the post-production team.
Mr Hu Xijin, the editor-in-chief of China's nationalist tabloid Global Times, has also entered the debate, accusing the pro-independence supporters in Taiwan of being narrow-minded and splitting hairs.
The video has received 35,000 dislikes and only 8,500 likes as of Tuesday (April 7). There were also more than 6,600 comments, with most of them criticising China.
In a likely reference to the online furore, Tsai said on Facebook on Monday that she felt "insignificant" at the present moment and thanked fans for their support, despite how they would view her in future. Chan has so far not commented.