Changing screen resolution is cutting the very edge of my screen off

So im working on my menus and ive included an option to change the resolution of the screen ingame, all of it seems to work relatively fine, however ive noticed that on certain resolutions the very edge of the screen gets cut off.

to explain further im working on a 2d platformer and the player needs to jump off walls, ive built my test levels in the 16:9 aspect ratio but when changing to a resolution of a different aspect ratio it seems to be cutting the edges off my screen

is there any way to prevent this from happening? its important that my player be able to see the edges of the screen at all times, i know it is possible to make a GUI stretch with screen reolution but is it also possible to do this with the camera

heres a really rough picture to try and illustrate what im saying, as you can see in the left image it cuts off the screen wheras in the right image it doesnt

any help would be greatly appreciated, working in c# if that helps