Feature update 1909 to 20H2 doesn't work

Hi,

I wanted to test the feature update to 20H2 (kb4562830) from a W10 1909 computer but it doesn't work. wsusoffline successully installed all latest updates from july 2022 (well actually may 22, the last available) but then it says there are no more updates to install, even after a few restart. When I generated updates, kb4562830 was downloaded and is correctly defined in "StaticDownloadLinks-w100-19041-x64-glb.txt" (don't know if it's the correct file it should be in though) so why isn't it installed ?

also note that when I launch updateinstaller the option "feature update via enablement package" is grayed out but I don't think I need to check this option as 1909 is now expired and feature update must enforced

I have Wsusoffline 12.6.1

thank you