does anybody know whats causing this? i've tried adjusting the principle bsdf, nothing affect by it, i can only pinpoint that the glass is the reason it becomes pale, because when i remove the glass, it doesnt happen to the whiskey inside. the only solution i've found right now is to make the glass fully transparent, but then it will look like my character is holding an invinsible glass
In Eevee, an object that has a Glass node or Transmission at 1 won't let correctly see another object that has Alpha Blend selected or Screen Space Refraction activated, so you need to find a trick to make your glass work.
For example you can mix Glossy and Transparent, with an Input > Layer Weight as factor, to make your glass:
For the liquid, make it Opaque in the material settinfs and give it a bit of Roughness so that it looks a bit opaque:
You can also mix the setup with a Glass node (or a Principled BSDF with Transmission at 1). In that case don't forget to activate the Screen Space Reflections, then the Refraction option in the Render panel :