I got this annoying problem two days ago. It was working perfectly all the time.
Model LG-49LJ594V | Purchased Date 13/03/2018 (UK, Scotland)
https://www.lg.com/uk/support/support-product/lg-49LJ594V
Watching my TV through antenna or WiFi. No cable from the Virgin box.
Did the reset. Thanks Mr Ang. Helped now. Needed to do Auto tuning for the Freeview program list.
Cheers, Egils