remove background button transient

Could you please post screenshots with all the pertinent Panels (Toolbar, Layers, Options Bar, Contextual Task Bar, …) visible to illustrate what you are talking about? 

An automated process like »Remove Background« is bound to work better on some, worse on other images, so it would be relevant to see what the images that produce bad results for you actually look like. 

The feature is contextually dependent on the layer properties, consider the following:

Another option is to use a script, which can be installed and run from the File > Scripts menu and also accessed via a custom keyboard shortcut, or put into an action with or without an F-key shortcut:

https://community.adobe.com/t5/photoshop-ecosystem-discussions/lost-quot-remove-background-bar-quot/m-p/15429202#M875668