I am having a really hard time finding what could be wrong here. I need to have a basic transparent glass, with some light reflections but still transparent. Just how the glass is in the real world. It seems great to me finally but in some angles (from which I also need renders) there is a weird reflection that is not transparent at all so it looks like a mirror. I searched a lot, but I could not find anyone having a similar issue. I tried glass materials from blenderkit/youtube/mine and it is a thing with every glass material so I guess there is a problem somewhere else. It is even weirdly deformed right where the reflection starts. I am not sure, how to attach the project here so I tried to screenshot everything. I would really appreciate any help, thank you very much in advance.
Check that your normals are pointing in the right direction and that your glass has 'thickness' rather than being just a single face. Reflection like that which your are seeing would indicate that the normals are pointing in the wrong direction, resulting in "total internal reflection" when light is incident at above the critical angle.