It's not immediately clear if this is due to some issue with the data, or due to some error in the visualisation. This particular example is for WSS (on Scotland), and may be related to covid-policy-modelling/temp-issues#17, so that should probably be addressed first, then re-tested.
One simulation has resulted in an extra line on some charts, which seems to connect the first point to the last point in a curve (see https://covid-modelling-stg.epcc.ed.ac.uk/simulations/102?model=wss).
It's not immediately clear if this is due to some issue with the data, or due to some error in the visualisation. This particular example is for WSS (on Scotland), and may be related to covid-policy-modelling/temp-issues#17, so that should probably be addressed first, then re-tested.