I have created a block view with title and image using fields. When I use the default image styles, they work as they should.
The custom image style I created is a thumbnail (120 x 70) with canvas. When I try using this style in Views, I get the original image size.
Have you checked the image preset is created fine after applying the resize/crop function on admin>config>media>image-styles
Just check the thumbnail(right one) is created fine by clicking on it.
Now when we add any image field in any view, make sure to use this style for display of this field
Please check with these points. And it works with Global text fields also.
If you are using it in a Global Text Area field and using the token to display it, it will not use the image style