@Vinayv4v's image in Post 2 will show you only whether a Layer is set to be Frozen within newly-created Viewports. But a Layer can also be Frozen within a specific Viewport whether or not it is set that way for new ones. Double-click inside a Viewport in a Layout so that you are in Model Space through it, and pull down not the general Layer Manager [the Layer Properties item in the image] but the simpler Layer listing pull-down, and see whether the Layer in question is Frozen in that Viewport, as the TEST Layer is here:

If a Layer that you want to show in that Viewport has that snow-flake in the corner of the circled icon, it's Frozen in that Viewport -- pick on that and the snowflake will turn into a sun, and the Layer will show [barring other complications such as the result of a command such as HIDEOBJECTS].
Kent Cooper, AIA