] key acts like it's held down even though it isn't stuck

Open the on-screen keyboard (search osk) and watch it, if the ] key highlights on its own the signal is coming from the keyboard controller, not the driver. Then plug in a USB keyboard and see whether the phantom typing continues, if it does, something else is sending it, a bluetooth keyboard still paired, a controller, a macro tool. Unplug and unpair everything. If only the laptop keyboard does it and cleaning didn't help, it's usually the membrane under that key or liquid, and the fix is disabling the internal keyboard in Device Manager and using an external one, or a keyboard swap which is cheap on most laptops.