Topics often suppressed by the Chinese government within its borders, including Tibet, Hong Kong protests and the Uyghur population, appear to be unusually underrepresented on TikTok compared with Instagram, according to a report published Thursday by online researchers. The findings could add to a wave of concern that Beijing may be influencing content on the popular video platform. TikTok is owned by ByteDance, a Chinese company. The report, from the Network Contagion Research Institute at Rutgers University, analyzed the volume of posts with certain hashtags on TikTok and Instagram, which…