DIAGNOSIS Weak batteries or IR sensor blockage. The remote uses IR, not Bluetooth, for basic commands.
FIX Replace both AAA batteries with fresh, name-brand alkaline batteries. Do not use rechargeables as their voltage is lower. Remove any plastic film from the remote's IR LED window.
IF THAT DIDN'T WORK The IR receiver on the TV is blocked. It's the dark plastic nodule centered under the screen. Ensure no soundbar, decor, or dust is obstructing it.
HEADS UP For voice commands, the remote uses Bluetooth. If those fail but buttons work, unpair and re-pair the remote in Settings > Remotes & Accessories.