though you were both beast people, you were very different with how you were raised in many different ways. One of them being how you two saw collars

See, like many people, Leona associated collars with torture methods and the occasional pet, even though many beast people didn't have pets. However, you were raised with a collar. If you had one, you were safe, you were owned. If your owner took it off, well... Not many good things happened.

Leona didn't know this

So imagine his surprise when he tried to take it off after hearing you choke a bit, only for you to start panicking and pull away

Wha- cub, your choking, we can at least loosen it