First, also test a current LE13 image in case it's something already resolved?
If not resolved, have a look in https://test.libreelec.tv/12.0/Generic/Generic/ and starting with the oldest development image (at the top of the file listing) to see if that has the same issue. If no problem we need to "bisect" (a halving process) the list of images to find out when the breaking change has occured; we can then cross-reference that to changes in GitHub. If the same issue is present and there are success reports from other users, I'm not sure we will figure it out easily as LE11 images were deleted when development switched to LE13.