MQTT shows no data when dashboard timewindow in the future

MQTT data is showing “No Data” when the timeframe shows up into the future (e.g. now+3m). i have a dashboard, where my solar energy is shown including forecast-data, and additionally i want to reflect the current energy values taken from mqtt-broker, but that doesn’t work.
any idea how to solve this?

Which dashboard is it? Grafana or the product dashboard?

Is the data forecast saved in mqqt or is it dynamic extrapulated from historic data but not from persissted data

it is a grafana dashboard, where i added a widget mit mqtt datasource. there is no persisted data as far as i know, i except to get the data in realtime from mqtt-broker (from the datasource).