Hi, I had the same problem, had mine for over 2 years and it had exactly the same symptoms (many people having them after updates).
Luckily LG are still replacing these F.O.C under an extended good will warranty.
Go here : http://www.lg.com/uk/support/warranty or here :
http://www.lg.com/uk/support/contact-customer-support
I asked for a warranty repair (even though its past 24 months) and they have arranged a free pickup (inPost in UK), repair and free return.
Outstanding service from them (and no, I do not work with LG or have any affiliation).