Grouped bar chart leaves gaps when some traces have no values for an x-axis tick

I’m trying to create a grouped bar chart with multiple traces (e.g., 5). For certain x-axis ticks, not all traces have values. When a trace has no value for a tick, Plotly currently leaves an empty space in the group, which creates unwanted gaps in the bars. Additionally, when the last trace is missing, the bars can look not centered, which makes the chart visually misleading.

Proposed behavior:
If only 4 traces out of 5 have data for a given x-axis tick, Plotly should render just 4 bars side by side without reserving space for the missing trace. This would make grouped bars more compact and visually accurate.

Note that this is the same problem as in this closed issue that was never resolved: https://github.com/plotly/plotly.js/issues/930

Riproduci un grafico a barre raggruppate con cinque serie, in cui una o più serie non abbiano valori in corrispondenza di determinate tacche dell’asse x, e confronta il risultato con il comportamento descritto nell’issue chiusa #930. La modifica è completa quando le serie mancanti non riservano più spazi vuoti e le barre rimanenti restano visivamente centrate all’interno di ogni gruppo.