Unverified breakpoints after 2.12.1 release

The report only identifies launch.json and the Firefox debugger configuration; no source file, test, or entry point is named. First reproduce the unverified-breakpoint behavior with the supplied multi-tab and pathMappings setup in VS Code 1.96.2 and extension 2.12.1, then investigate debugger attachment and breakpoint verification; done means breakpoints remain verified and appear in the IDE across the reported tab setup.

Type: Bug

launch.json configuration:

{
            "log": {
                "fileLevel": {
                    "default": "Debug"
                },
                "fileName": "${workspaceFolder}/logs/ffdebug.log"
            },
            "name": "FFdebug",
            "pathMappings": [
                {
                    "path": "${workspaceFolder}/app/",
                    "url": "http://127.0.0.1:5500"
                },
                {
                    "path": "${workspaceFolder}/app/",
                    "url": "https://proto.example.com/"
                },
                {
                    "path": "${workspaceFolder}/app/",
                    "url": "https://stage.example.com/"
                }
            ],
            "preLaunchTask": "Firefox debugger",
            "request": "attach",
            "skipFiles": [
                "**/js.stripe.com/**/*",
                "**/static.sumsub.com/**/*",
                "**/node_modules/**/*",
                "**/*.min.js",
                "${workspaceFolder}/app/lib/tools.js"
            ],
            "host": "127.0.0.1",
            "type": "firefox"
        }

After upgrading to 2.12.1 release and restarting the debugger, I'm unable to verify any of the breakpoints. I have tried to restart both the IDE and the browser to get it to work, but then it would catch a breakpoint in the newly opened tab and don't show it in the IDE.
I have to close all tabs in the browser but one and restart the debugger to connect it again.

Extension version: 2.12.1
VS Code version: Code 1.96.2 (fabdb6a30b49f79a7aba0f2ad9df9b399473380f, 2024-12-19T10:22:47.216Z)
OS version: Windows_NT x64 10.0.19045
Modes: