Annotated heatmap numeric axis label issue

I wanted to have numeric labels for the plotly annotated heatmap using the plotly.figure_factory.create_annotated_heatmap.

Below is the code to reproduce it:

import plotly.graph_objects as go
from plotly.subplots import make_subplots
import plotly.figure_factory as ff
import numpy as np
fig = make_subplots(rows=n_rows, vertical_spacing=0.0,horizontal_spacing=0.0,shared_yaxes=True,shared_xaxes=True)
anno = list()
for row in range(n_rows):
    annotation = test.iloc[[row]].applymap(lambda x: x if (x==test.iloc[[row]].values.max() or 
                                                           x ==test.iloc[[row]].values.min()) else " ")
    fig1 = ff.create_annotated_heatmap(z=np.array(test.iloc[[row]]), x = cols, 
                                       y=[test.iloc[[row]].index[0]], showscale=False,colorscale=colorscale,
                                      annotation_text = np.array(annotation),
    fig.append_trace([0], row=row+1, col=1)
    anno += list(fig1.layout.annotations)

for ann in anno:
    if test.index.tolist().index(ann['y'])!=0:
        ann['yref'] = 'y'+str((test.index.tolist().index(ann['y']))+1)

# fig.update_xaxes(showticklabels=False, fixedrange=True)
# fig.update_yaxes(fixedrange=True)

# fig.layout.update(clickmode='select')
# config =  dict({'scrollZoom': False,'dragModeBar':False})
# fig.layout.update(dragmode=False)


below is the test dataframe:

and below is the cols variable having all elements of type string:

and below is the resulting plot:

Does anyone know the reason for this and a fix?