As far as I can see, the problem is not with the browser or theme but solely with Windows. The emoji is rendered as an img under Windows since otherwise, Windows can’t display it correctly. There’s nothing we can do about it.
If your customer insists on including emojis in their titles, you can overwrite the default CSS remove the justify-content, and give the button a margin-left: auto instead or work with floats.
Source ChatGPT: Why does Windows render emoji as img?
Windows renders emojis as images in certain cases because it does not use a true native emoji font in all applications. Instead, Windows relies on a system called “Segoe UI Emoji”, which contains glyphs for emoji characters. However, how these emojis are rendered depends on the application and the Windows version.
Reasons Why Windows Renders Emojis as Images
Lack of Native Color Font Support in Some Apps
Windows uses Segoe UI Emoji as the default emoji font. While this supports colored emojis, many applications (e.g., Notepad, some browsers) don’t fully support color font rendering.
Instead, these applications may render emojis as black-and-white glyphs or fall back to image-based rendering.
Web Browsers and Custom Rendering
Some web browsers (like Chrome, Edge, and Firefox) may override Windows’ emoji rendering and use Twemoji (Twitter Emoji), Noto Color Emoji (Google), or Apple’s emoji set by loading emojis as images instead of relying on the system font.
Windows Falls Back to Bitmap Images for Some Emojis
When an application doesn’t fully support OpenType-SVG fonts (the format Windows uses for color emojis), Windows may fall back to rendering emojis as bitmap images instead.
Variable System Behavior in Different Windows Versions
Older versions of Windows (pre-Windows 10) didn’t support color emojis at all, so they always used black-and-white glyphs or images.
Windows 10 and later introduced OpenType-SVG emojis, but some legacy apps don’t support this format correctly.
Scaling & Consistency
Rendering emojis as images ensures consistent display across different screen resolutions and devices.
It also allows Microsoft to update emoji designs without relying entirely on font updates.