[Gameplay] Master Yi under Highlander not rooted when flinged into Singed's Mega Adhesive

[Gameplay] When playing Singed since the rework, flinging enemy champions into Mega Adhesive has been the most important mechanic as it roots them for a long ass time. But this doesn't work on Master Yi under Highlander. Highlander gives slow immunity, but rooting shouldn't be denied, else it should be specified in Singed's W description. There are some clips already (the issue is ~7months old) that showcase it.

I'm not using the client 'Report a bug' because I can't seem to use for some reason