Charts are being automatically missconfigured on dashboard

Hi,

I have a dashboard that have combination charts, and frequently those charts are being altered without being changed by anybody.

On the prior day, they look like this:

Please note that the only line is the purple one, all the others are bars.

But on the other day it gets like this:

The green one becomes a line too, and it should keep being a bar.

Does it happen to somebody else?