This page explains in detail the interactions between the Sonic series and the Transformers series.
Sonic the Hedgehog (IDW) issue 44[]
September 15, 2021
ARGUABLE LINK
Sonic
Transformers
On page six of the comic, Dr. Starline is keeping the robot Belle the Tinkerer strapped to a table to study her, and on a shelf in the background there's what appears to be the Matrix of Leadership from the Transformers series. It can be seen partially covered in the second panel, and it's completely visible in the last panel, where Dr. Starline also says "There's more to you than meets the eye", a reference to the Transformers quote "more than meets the eye".
Because of it being an inanimate object of unknown function and also due to unclear license, it can't be said for sure if the object in the background should be considered an actual version of the Matrix of Leadership or just an item that happens to look like it, in which case this would count as a out-universe (or type 3) link rather than an in-universe (or type 1) link.
License[]
IDW, which published the Sonic the Hedgehog comic, also publishes Transformers comics, so it's possible that the authors were allowed to include elements from said series. In any case they only included a minor reference.