Environment

Vuetify Version: 3.11.0-beta.0
Vue Version: 3.5.24
OS: Windows 10 (current)

Steps to reproduce

1. Initialize a v-calendar component with type="month"
2. Bind v-model to a ref containing a single date string (e.g., '2025-11-16')
3. Click on multiple different dates sequentially (e.g., click Nov 24, then Nov 25, then Nov 26).

Expected Behavior

The component should respect the single-string v-model binding. When a new day is clicked, the visual selection should move to that new day, and the previously selected day should be deselected.

This is the standard behavior for single selection, and it works correctly in type="week" view. The bug only appears in type="month" view.

Actual Behavior

When a new day is clicked in type="month" view, the component adds the new day to the visual selection. The previously selected day is not deselected.
This leads to a visual bug where multiple days are highlighted simultaneously.

Reproduction Link

https://play.vuetifyjs.com/#...

Images