Created attachment 183005 [details] document with SmartArt diagram for testing Open attached document. It has a SmartArt shape. Ungroup the SmartArt shape. Save the document to odt-format. Reopen the saved document. => The SmartArt-shapes are totally wrong. It is a problem in Writer. The same steps work without problems in Impress. I wonder why it does not work. Do this: Save the original file to odt-format. That generates a group from the SmartArt shape. Open that file and ungroup the shape. Save it and reopen it. Now the ungrouping works without problems.
Created attachment 183010 [details] What I see at every step. File showing what I see at every step. - Selecting the object before ungroup. - Selecting after ungroup. - Selecting after save-reopen as odt. Except for the strange blue rectangle before ungroup that disappear after ungroup, I have not clear the issue.
To get a true group on opening the file you have to check the option "SmartArt to LibreOffice shapes or reverse" in Tools > Options > Load/save > Microsoft Office. Otherwise a SmartArt shape is imported as metafile in Writer. Please try again with this option checked.
Created attachment 183018 [details] Document with what I see with the SmartArt option enable. Thanks, @regina, I can see and confirm the issue now. Version: 7.5.0.0.alpha0+ (x64) / LibreOffice Community Build ID: a7683a16e98def4198e1f74a93fecdaacbf639e7 CPU threads: 4; OS: Windows 10.0 Build 19044; UI render: Skia/Raster; VCL: win Locale: es-ES (es_ES); UI: en-US Calc: CL threaded Jumbo