iPhone randomly playing TikTok audio in the background with no apps open

My iPhone will randomly play audio of what sounds like short videos, always from the same person’s chanel that I watched one video on one time using the TikTok website. (I don’t have a TikTok account, nor do I have the app installed.) I’ve noticed it more frequently happens when I “long hold” something to copy it (like a web link in a text message) but not always. Sometimes that doesn’t start the phantom audio, and other times it starts when I’m not copying anything at all. It usually stops at the end of the first video’s audio, but sometimes it’ll go ahead and play the audio from a second video or repeat the same one again.