I couldn't find the answer on the Kodi forum
YouTube is something that periodically breaks due to upstream Google API changes, so you'll see periods where the developer(s) push updates and make releases via the upstream GitHub (code) repo, but the Kodi (add-on) repo remains outdated for a while until the changes are fully addressed. If the author pushes updates to the Kodi repo users expect the add-on to work, so it's often better for the authors to leave something broken until fixed than deliver partial fixes that attract more support noise.
I am running YouTube add-on version 7.1.1.6 and there may even be newer versions. You have to join the YouTube Add-on thread at the Kodi Forum webpage. Here's a link:
They make it hard to find the download sources, so you'll have to thumb through the recent few pages to find them.
