After clicking the button "Generate Report", the title of the browser tab changes from "VISART" to "Updating...". When the report is generated the title is "VISART" again. While the generation is in progress, "Generating..." or "VISART: Generating..." would fit better.
It seems there is no practical way to handle this. Dash offers loading_state property for each component. This is useable (callable) via CSS or JS codes.
Since page title cannot be modified by CSS settings, the most preferable way is calling some JS codes via Clientside Callbacks. However, it is not possible to access loading_state property from main code, which is necessary for catching loading state. The only way is to write a Dash component via Reach framework (like other Dash components). That seems not feasible at the moment.
Dash offers changing or removing "Updating..." text via: app = dash.Dash(__name__, update_title=None). Maybe this one can be tried.