heatmaps hide data if any X- or Y-axis label is repeated (px.imshow and go.Heatmap)

This example is from Customizing the axes and labels on a heatmap:

import plotly.express as px
data=[[1, 25, 30, 50, 1], [20, 1, 60, 80, 30], [30, 60, 1, 5, 20]]
fig = px.imshow(data,
                labels=dict(x="Day of Week", y="Time of Day", color="Productivity"),
                x=['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday'],
                y=['Morning', 'Afternoon', 'Evening'])
fig.show()

If you change "Friday" to "Monday", or "Evening" to "Morning", the row or column with the repeated label disappears. The same thing happens with go.Heatmap on the same page.

I don't think I read anywhere that labels must be unique, and all the examples suggest that the labels are arbitrary strings. If they must be unique, reporting an error seems more rational than hiding data.

Inizia eseguendo l'esempio px.imshow fornito, cambiando Friday o Evening in un'etichetta ripetuta, e riproduci la riga o la colonna mancante. Confronta il comportamento con go.Heatmap usando gli stessi dati; il lavoro è completato quando le etichette ripetute non nascondono più silenziosamente i dati, oppure un errore chiaro segnala che non sono supportate.