Pinterest displays mobile layout when add-on is enabled

[imheinrichlunge]

Description
When using the Side View add-on, Pinterest renders its mobile layout instead of the desktop version. This negatively affects usability and layout, even on larger screens, specially in post pages.

Steps to Reproduce:

1. Just open Pinterest with add-on enabled.
   Observe that Pinterest loads in its mobile layout, despite a desktop environment.

Expected behavior
Pinterest shouldn't render its mobile layout if Side View isn't being used.

With add-on disabled (desktop layout):

With add-on enabled (renders mobile layout):

Environment:

• OS: Windows 11 Pro 23H2 22631.5189 Windows Feature Experience Pack 1000.22700.1077.0
• Firefox version: 137.0.2 (64-bit)
• User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:137.0) Gecko/20100101 Firefox/137.0
• Side View version: 0.6.6956

Screen Metrics

• Viewport: 1920 × 919 px
• Device Pixel Ratio: 1
• Full screen resolution: 1920 × 1080

Edit

These are the add-ons I'm currently using: