bt.plot(): TypeError: float() argument must be a string or a real number, not 'Timestamp'

Expected Behavior

bt.plot()

plot

Actual Behavior

TypeError                                 Traceback (most recent call last)
Cell In[61], line 1
----> 1 bt.plot()

File ~/miniconda3/envs/tensorflow/lib/python3.10/site-packages/backtesting/backtesting.py:1592, in Backtest.plot(self, results, filename, plot_width, plot_equity, plot_return, plot_pl, plot_volume, plot_drawdown, smooth_equity, relative_equity, superimpose, resample, reverse_indicators, show_legend, open_browser)
   1589         raise RuntimeError('First issue `backtest.run()` to obtain results.')
   1590     results = self._results
-> 1592 return plot(
   1593     results=results,
   1594     df=self._data,
   1595     indicators=results._strategy._indicators,
   1596     filename=filename,
   1597     plot_width=plot_width,
   1598     plot_equity=plot_equity,
   1599     plot_return=plot_return,
   1600     plot_pl=plot_pl,
   1601     plot_volume=plot_volume,
   1602     plot_drawdown=plot_drawdown,
   1603     smooth_equity=smooth_equity,
   1604     relative_equity=relative_equity,
   1605     superimpose=superimpose,
   1606     resample=resample,
   1607     reverse_indicators=reverse_indicators,
   1608     show_legend=show_legend,
   1609     open_browser=open_browser)

File ~/miniconda3/envs/tensorflow/lib/python3.10/site-packages/backtesting/_plotting.py:613, in plot(results, df, indicators, filename, plot_width, plot_equity, plot_return, plot_pl, plot_volume, plot_drawdown, smooth_equity, relative_equity, superimpose, resample, reverse_indicators, show_legend, open_browser)
    611 ohlc_bars = _plot_ohlc()
    612 _plot_ohlc_trades()
--> 613 indicator_figs = _plot_indicators()
    614 if reverse_indicators:
    615     indicator_figs = indicator_figs[::-1]

File ~/miniconda3/envs/tensorflow/lib/python3.10/site-packages/backtesting/_plotting.py:573, in plot.<locals>._plot_indicators()
    568     r = fig.line(
    569         'index', source_name, source=source,
    570         legend_label=LegendStr(legend_label), line_color=color,
    571         line_width=1.3)
    572 # Add dashed centerline just because
--> 573 mean = float(pd.Series(arr).mean())
    574 if not np.isnan(mean) and (abs(mean) < .1 or
    575                            round(abs(mean), 1) == .5 or
    576                            round(abs(mean), -1) in (50, 100, 200)):
    577     fig.add_layout(Span(location=float(mean), dimension='width',
    578                         line_color='#666666', line_dash='dashed',
    579                         line_width=.5))

TypeError: float() argument must be a string or a real number, not 'Timestamp'

stats = bt.run() works fine.. not sure why I can't plot

• Python: 3.10
• Backtesting version: 0.3.3
• bokeh.version: 2.4.3
• OS: MacOS Ventura 13.1