STOCKHOLM—H&M vowed on Wednesday to win back trust in China amid growing signs its fashion empire is suffering from a backlash after it voiced concerns last year about alleged human rights abuses in Xinjiang province. The comments come as Western brands battle to strike a balance between consumers in the world’s second-largest economy and public opinion at home, which has become increasingly concerned about reports of forced labor in Xinjiang. China denies the reports. H&M, which also reported a quarterly loss due to the continued closure of some of its shops in the pandemic, has come under fire from consumers and officials in China after one of its statements from 2020 resurfaced on social media. In it, the world’s second-biggest fashion retailer expressed concern about the allegations of forced labor in Xinjiang and said it would no longer source cotton from there. China is H&M’s top clothing supplier and the …