Since this feature hit my browser after an update a while ago, I'm constantly annoyed by it. I've been dragging tabs all the way to the left to rearrange them practically forever, and now suddenly doing this is pinning tabs that I don't want to pin - I'm just trying to rearrange my tabs.
Perhaps I'm in the minority here, and that's fine - this feature can be enabled by default; however, an option to disable it altogether (via settings or even an about:config option) would go a long way. This feature greatly disrupts my workflows and has proven to slow me down when I'm in my flow state while developing websites. I need this feature to be toggle-able to continue using Firefox as my daily driver browser.
Update 2025-09-29: This feature can now be (mostly) disabled via an about:config option (as of v143.0.3). Setting "browser.tabs.dragDrop.pinInteractionCue.delayMS" to any relatively high value should effectively disable the option. The value is the number of milliseconds before the pin tab option triggers. I set mine to 2000, requiring a full 2s before the feature triggers, which has generally solved the issue for me. I encourage you to adjust this config option to your liking once your browser is updated to at least 143.0.3
