There are several possible steps to consider when troubleshooting delays when using a Smart TV remote:
Try unplugging and plugging the TV back into the outlet. This may reset the system.
Ensure that the remote is correctly synced to the TV.
Replace the batteries of the remote.
Ensure that there are no physical obstructions between the remote and the TV, such as furniture.
Check to see if the remote is correctly programmed for the make and model of your TV.
Check to see if there are any software updates available.
