I thought the Firmware & webOS might be different. But it doesn't look like it.
In LG Smart+ TV, go to Settings > Quick Settings > General > About this TV > webOS TV Version.
https://webostv.developer.lge.com/common-page/faqs/general-how-check-platform-version-my-tv/?&ccm_paging_p=3
So you may already be at webOS 5