DIAGNOSIS: That's the sound of the plastic TV frame and the internal metal chassis expanding or contracting slightly with temperature changes. The mini-LED backlight system generates heat, and when it cools down after being off, the different materials contract at different rates, causing clicks and pops.
FIX: There's no actual "fix" because it's not a malfunction—it's a physical characteristic of this model's construction. You can try to minimize it by ensuring the TV has decent ventilation around the back panel so heat dissipates more evenly, which might reduce the thermal stress.
IF THAT DIDN'T WORK: If the clicking is loud, rapid, or happens constantly while the TV is on (not just at power on/off), that could point to a failing power supply component or a loose internal bracket. In that rare case, you'd need to have it serviced.
HEADS UP: Don't confuse this normal thermal noise with the distinct sound of electrical arcing (a sharp, loud *snap*), which is a serious issue. The normal sounds are subdued plastic creaks, not sharp electrical snaps.