Help with grafana

[jt1971]

I think I've set up prometheus correction; am getting meaningful output when I look on webpage through port 9898
However, when I setup Grafana data source - the following error:
Error reading Prometheus: bad_response: readObjectStart: expect { or n, but found #, error found in #1 byte of ...|# HELP tado|..., bigger context ...|# HELP tado_activity_heating_power_percentage The %|...

Looking at webpage data, in amongst the tado_sensor data, there are every so often two lines which say:

HELP tado_sensor_temperature_value The temperature of a specific zone in celsius degres.

TYPE tado_sensor_temperature_value gauge

These seem to be the issue. Sorry for the ignorant question, but any thoughts?