rqt_plot stops plots only zeros

edit

rqt_plot was working fine, but now only plots zeros no matter what values I sent to it. And yes, I've zoomed in and the values really are zero, even though I'm sending a sawtooth plot between 5 and -5.

I've tried uninstalling and installing but the same problem. I notice it retains it's plot configuration (i.e. the message it's plotting) thru the uninstalling and installing process, so there is a config file somewhere. I'd like to delete this file and see if plotting function returns.

Any ideas?