I had a similar problem that my LG store was empty. There were no apps any more. It has been working for years but not any more.
Other apps still worked fine, could use Netflix and YouTube. Could use the web browser without problems.
The LG TV was using a wired connection and I could see it in the network.
After a long search on the internet I decided to change the Network setting. Instead of DHCP (automatic) I gave it a fixed IP address and used 8.8.8.8 as DNS server and.....the store started to work again.
Very strange but maybe this story could help you update your apps.
Good luck.