Headphone mode keeps toggling between ON and OFF on its own. How to fix this?

My Xiaomi phone keeps switching from "headphone mode" to "normal mode" constantly (~2-3 times per second), completely on its own. This persists even if headphones are actually plugged in. Before this is marked as duplicate, questions like [this one](https://android.stackexchange.com/questions/5109/how-do-i-toggle-headset-headphone-mode-manually?newreg=9c86d51a3386473db78a4bcb981b55d0) and many others on the internet have the issue where their phone is stuck in headphone mode, not toggling on its own, so the solutions therein don't work. I tried: - Cleaning the headphone jack - Plugging headphones in, turning the phone OFF, then ON, and unplugging. - Downloading "toggleheadset" apps. These work in the sense that if headphone mode is ON it switches it off and viceversa, but 0.2 seconds later it changes again on and off and on and off and on and off... There must be some way of "disabling" the headphone jack completely (I have a Bluetooth headset so idc). Resetting the phone should be a last resort, and I don't think it would fix it. Edit: following beeshyams' comment I went into Safe mode, but the behaviour persisted. I tried "disable headphones" apps but they did nothing. Finally I did a hard reset, but this didn't fix it either :/