16:9 and 1920x1080 displays differently

All of the default ratios display fine, 4:3, 16:10, etc.
The camera's orthographic size automatically switches itself from 7.5 to 10 and I can't seem to stop it.
Intended display size at 16:9--
This is what happens when I change it to 1920x1080--

I can't find a way to lock in the orthographic size. I'm using cinemachine and pixel perfect camera stuffs and a cinemachine confiner to separate rooms.

I tried to programmatically set the ortho size of the camera in my room manager, but no dice.
Here is said room manager if that helps. I'm at a bit of a loss.

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class RoomManager : MonoBehaviour
6. {
7.    
8.     public GameObject virtualCam;
9.     public Camera orthoCam;
10.    
11.     private void OnTriggerEnter2D(Collider2D other)
12.     {
13.         if(other.CompareTag("Player") && !other.isTrigger)
14.         {
15.             virtualCam.SetActive(true);
16.             orthoCam.orthographicSize = 7.5f;
17.         }
18.     }
19.     private void OnTriggerExit2D(Collider2D other)
20.     {
21.         if(other.CompareTag("Player") && !other.isTrigger)
22.         {
23.             virtualCam.SetActive(false);
24.         }
25.     }
26. }

Any help is appreciated, thank you!