1. Open Impress, add shape 2. With the shape selected, Custom Animation Sidebar deck, add an animation 3. Select a placeholder box 4. Select shape again The Add button is now in a non-working state. Step 3 is important: if you simply deselect, the problem does not appear. Bibisected with linux-64-6.1 to d799436414ab7e28b6bf9a918fd3779b3fc85008 tdf#116342 Allow selecting text boxes anywhere by default The commit is small and innocent, so it is strange that it would cause this, but here we are.
Reproduced in: Version: 24.8.0.0.alpha0+ (X86_64) / LibreOffice Community Build ID: 3be785e088cc0aa726509cf6b52b1d3b03817172 CPU threads: 8; OS: Linux 5.15; UI render: default; VCL: gtk3 Locale: en-AU (en_AU.UTF-8); UI: en-US Calc: threaded