[Gameplay] Cannot devour idle Fiddlesticks as Tahm Kench

In ARURF, I just played Tahm Kench with a Fiddle on my team. Throughout the game, I was unable to devour (W) Fiddle. Note that Fiddle was not in a cast (W) or stasis (Zhonyas). Asked Fiddle to idle for repeated attempts. No issues while devouring other allies (Rengar, Jax).

1. Play Tahm Kench with Fiddle.
2. Try to Devour (W) Fiddlesticks.
3. Fail.

I tried reproducing the bug in a custom game and was unsuccessful.

Browsing the internet, I found multiple people that have encountered the same problem since 2016: 1; 2; 3.

Video of my desperate attempts at eating Fiddlesticks

Best, a Potato Brain.