Steps to recreate: Connect to Playback-MR. (I'm going to guess this happens in LIVE too).
I do have a SuperDOM open, but I don't think that is related.
1) Start playback. Get some candles in there.
2) Draw an object (line/box, etc).
3) Then Click the dataseries (will get the circles).
4) Then DRAG the dataseries, click on it and hold the mouse pointer down. (This is valid movement for moving to another chart). Start to move it some where. You'll see a box follow the mouse around.
4-update) Follow on testing shows this will also happen with an EMA/SMA (click to drag it and move it but leave on same chart, chart drawings disappear).
But DO NOT move it to another chart. Stop - let go of the mouse pointer.
Chart drawings disappear. They are still in the Drawing Objects list, shown as visible. I did try to uncheck and recheck with apply - they did not return.
*I couldn't find anything related with NT8 in search.

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