Since the issue is only happening in Miro (not in other apps), across all boards, and you're on Windows using a mouse, here are a few things you can try that often resolve cursor misalignment issues:
Reset Zoom Try pressing Ctrl + 0 to reset your browser zoom to default, then refresh the page.
Switch Browsers Open the board in a different browser (like Chrome, Firefox, or Edge) to check if the issue persists. Also, make sure your browser is fully updated.
Clear Browser Cache In Chrome: Settings > Privacy and security > Clear browsing data > Cached images and files
Check Extensions Try disabling any browser extensions, especially ones that affect page behavior (e.g. ad blockers, mouse tools, screen recorders).
If none of these solve it, feel free to share your browser version, and if possible, a short screen recording.