As often as I tried, no handles in a text box appeared to reshape the box.
Can you click Help > About LibreOffice then click the icon just after Version Information to copy the details. Paste the details in your question if you can still edit it (pencil icon) or a new comment.
The most likely reason you cannot access the text box handles is that the text box is in a larger group. Right click on the edge of the text box and select Enter Group F3. Depending on how many sub-groups there are you might need to enter group more than once.
What is shown in the status bar? Text Frame selected, Group object selected.
But in this case you will see the handles of the group.
Tested with Version: 24.8.7.2 and 25.8.0.4 on Windows.
Not necessarily, if the group is larger than the visible screen. I cannot think of any object with text and without selection handles.
The only other possibility is if the text box is on a locked layer where it is visible but not editable
nor selectable.
The text box is in a subsequent layer that I created. I did check the dialogue that opens with the Modify Layer selection - the layer is unlocked.
this is LibreDraw v. 25.8.1.1
This did not produce any result
Was the object created in Draw or did it come from another source?
If the object is an svg then you might need to use the Break command but that is quite destructive. I prefer to use Inkscape to gently unravel svg files, it keeps the grouping so not everything breaks apart at once.
In the attached .odg I have exported a text box to SVG but did not tick Selection only so I exported the page too. To modify the text/text box, click on the text and then click Shape > Break
TextBox&Page.odg (20.6 KB)
If it isn’t something like that, can you share a sample?
Have you try to select and reshape the text box with the Sidebar?