I have the same "Memory" problems, I run of Ethernet because the wifi is blanked out, I emptied the cashe and set for Private viewing, that seemed to work for a while but back to the same, having to switch off the app for the memory, also get the Network cable not connected, Network cable connected, that no one seems to have got fixed either!
I have come to the conclusion LG are just crap! This is my second LG tv , the one I had a few years ago was lcd, it had a good picture, but took 20 minuets to start, 13 months after buying! The sound was crap, I had new speakers and a new motherboard fitted, I stopped at £220 and binned it, looks like this piece of junk will go the same way, expensive lesson, So NOT buy LG!