Disable Nahimic service in Windows Services, and the problem is gone.

How-to: Disable Nahimic Service to fix high CPU and RAM problem – HAP|仲林 : THE ARTISTEER

By the way, this problem has been present since at least 2019 with Qt 5.13, hence it's more likely the fault of Nahimic-related software.

After searching for it, I still don't know why this method is useful, but I found that this software has caused widespread complaints (on other problems):

Nahimic is literally malware. : r/LenovoLegion

Nahimic service真是个奇葩的存在 - 电脑讨论(新) - Chiphell - 分享与交流用户体验