I solved the problem myself. The cause of the error was an Accolade Device. Removing the “!” symbol from the title inside the Device resolved the issue. This is a strange bug because (1) I used the “!” symbol in the titles of other devices as well, but removing it from that one made everything work properly; (2) My Accolade Device was created a long time ago and hadn’t been modified until the error occurred yesterday.
My approach to solving this was to delete all devices to first confirm if the problem was caused by a device, and then delete the devices in batches by type. After each deletion, I performed an Upload to Private to gradually narrow down the scope. Eventually, I conducted step-by-step troubleshooting in the problematic Accolade Device, carrying out about 13 tests in total.