When having charts open from tester runs (visual mode=true) at the time of exiting the JForex client, JForex will reopen the charts on the instrument that is the first in the workspace currencies list, regardless what instrument the tester runs were subscribed to.
As JForex isn't remembering the trade-charting objects or charting objects placed by the strategy code of a tester run anyway, best would be to just skip re-opening charts from previous tester runs.

Best, RR.