I still get these anoying black panels with v19, can't this problem can be fixed once and for all ?
Looks like a rendering order problem to me, but i know nothing about MT5 api
this problem exists on many versions now, so long ago that i can't remember when i first discover it (it was already present on MT4 versions if i remember well).

XARD: Place Xu Clean Screen file into your MQL5/Scripts folder -- Restart MT5 -- drag the script onto the chart -- you should see objects disappear on screen -- save as template -- Now select new template and all objects should appear on screen and work.

SOLESHOE: Thanks XARD, it worked !