@NikolaZ Is the firmware level a typo? I can only find 05.60.06 for your model:
[05.60.06]
1. LG Channel has been upgraded and service territory expansion. (Selected Countries Only)
2. Software update contains minor bug fix
If that is NOT what you have, then try downloading it onto a USB stck and update it manually, from here:
https://www.lg.com/uk/support/product/lg-55UH770V
If it IS already that version, then I would recommend you report this issue DIRECTLY to your country LG support, as this is ONLY a peer-to-peer enthsiasts site, NOT related to LG itself.