Pywinauto - COMError when selecting tabs

Question

I've been having a problem lately, when I select specific tabs (sheets) in excel documents, I get the following error:

c:\python27\lib\site-packages\pywinauto\controls\uia_controls.pyc in select(self, item)
    402     def select(self, item):
    403         """Select a tab by index or by name"""
--> 404         self._select(item)
    405         return self
    406

c:\python27\lib\site-packages\pywinauto\controls\uiawrapper.pyc in _select(self, item)
    604         if item_index < len(list_):
    605             wrp = list_[item_index]
--> 606             wrp.iface_selection_item.Select()
    607         else:
    608             raise IndexError("item not found")

COMError: (-2147467263, 'Not implemented', (None, None, None, 0, None))

This is the code:

app = pywinauto.Application(backend="uia").connect(process=43800)
tab_list = app.top_window().descendants(control_type="Tab")
tab_menu = tab_list[1]
tab_menu.select(1)

The excel document has multiple sheets.
The tab window is "uia_controls.TabControlWrapper - 'Sheet1', TabControl, 3527539".

It seems that the methods: get_selected_tab() and tab_count() work. So the only problem is the "select()" method which should actually select the tab.

I've tested it on multiple excel files, and in different environments (python2.7, windows 10 and windows 2016, with and without admin privileges)

What can be the problem here? Is there a solution or a workaround to this issue?

Thanks.