DragonBones in MonoGame - lags after few seconds

I’m working on adding the support for skeletal animations from DragonBones into Monogame.
I found https://github.com/DragonBones/DragonBonesCSharp and also a working demo https://github.com/trong8820/TestDragonBones.

However, after few seconds of animation playing I’ve noticed that the framerate drops significantly, and this happens even if I remove all drawing code from the library. So it must be something in the update function I think, but I was wondering whether anyone else also encountered issues with using that library in MonoGame?

I know this is an old topic.

Are you, by any chance, in possesion of this cloned repo (TestDragonBones)?
I’m looking for it, but it has been deleted from GitHub.