Text objects with no borders are hard to select properly in order to be moved in a slide. I have to move my mouse really carefully up until the cursor changes and hope I’m actually selecting the right element…
You can do that with the so-called “rubber band”:
Click, drag, release.
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With me Windows 10 Home; Version 1903; 64-Bit | LibreOffice, Version: 6.2.4.2 (x64).