Tab title does not sync when changing list of objects

The docs says:

The Tabs objects should never be modified directly. Instead, it is recommended to modify tabs using the provided methods, except when replacing the list of objects entirely. Using the methods ensures that the rendered views of the Tabs are rerendered in response to the change, but even more importantly it ensures the tab titles are kept in sync with the objects.

but with the following code, the tab title does not update:

import panel as pn
import panel.widgets as pnw

def show_row1(event):
    tabs.objects = [row1]

def show_row2(event):
    tabs.objects = [row2]

row1 = pn.Row('This is row 1', name='row1')
row2 = pn.Row('This is row 2', name='row2')
tabs = pn.Tabs(row1)
button1 = pnw.Button(name='button1', on_click=show_row1)
button2 = pnw.Button(name='button2', on_click=show_row2)

pn.Column(pn.Row(button1, button2), tabs).servable()

The alternative I use in general is to .clear() first and then repopulate but it seems to be slower.

Am I missing something or is it unexpected behavior?