Run `xprop | grep STRUT` and click on first panel then repeat with second panel. Post both output here.
But this is bug in `mate-panel`. The problem most likely is caused by new strut property! `compiz` is ignoring strut because "top" panel (panel over bottom panel) strut is not at monitor edge. If MATE support such configuration then it needs ensure that it correctly reports strut / reserved space.
Run `xprop | grep STRUT` and click on first panel then repeat with second panel. Post both output here.
But this is bug in `mate-panel`. The problem most likely is caused by new strut property! `compiz` is ignoring strut because "top" panel (panel over bottom panel) strut is not at monitor edge. If MATE support such configuration then it needs ensure that it correctly reports strut / reserved space.