Cannot resize existing textboxess

When editing a PowerPoint .pptx presentation in Impress, I cannot resize existing textboxes, as dragging the resize handles only moves the boxes instead of resizing them. When I create new textboxes, I can resize them with the same method just fine.

How can I resize existing textboxes? Is that a bug? Or am I missing some lock setting?

Build ID: 00(Build:2)
CPU threads: 8; OS: Linux 5.9; UI render: default; VCL: gtk3
Locale: en-US (en_US.UTF-8); UI: en-US
Calc: threaded

Check section Protect for option [x] Size selected (Right click the text box -> Position and Size ... -> Tab:Position and Size (but I’am not sure, since your description states dragging the resize handles only moves the boxes, while that option set would prevent to drag on the handles at all, but would turn the mouse pointer to a special “not-allowed” icon)

In section Protect, option [ ] Size is not selected.

Seems to be a bug there. I opened a .ppt file, and couldn’t resize a Title text (a forbidden symbol appeared). But after touching some other objects, I could resize the box. Tried, but can’t repeat. Protect size was unchecked. Tested with LibreOffice (x86); OS: Windows 6.1.

Same problem with me: CentOS 7.9 Linux, Libreoffice Version:

I try to edit a .odg file which is from 2017-01. “Protect” flag is not selected!

I found no real solution, but after some time and also trying out rotation mode (red frame / dots) of the text box it started to work, but NOT for all boxes!