1 Start with a fresh Writer document, 2 type some text (just "x"), 3 enable Bold (by any of the means of typing the Ctrl-B shortcut, or pressing the "Bold" icon in the Formatting toolbar, or "Format - Text - Bold", or even remotely dispatching <.uno:Bold> via UNO), 4 then directly afterwards do a "neutral" (in the sense that it doesn't click on anything sensitive like the header area) mouse-button-1 click into the Writer document area (e.g., anywhere in the empty document area beyond/below the text already typed): The Bold state is disabled again (the toolbar icon is unset, typing any further text will not be bold). This does not happen when the document is empty, i.e., when step 2 above is left out. The Bold state will then remain enabled after clicking into the document area. I can reproduce this at least back to "Version: 5.3.0.0.alpha1+ Build ID: 4136757b4e51c4e6f7cb4132c95538a7f831ef2c" (i.e., the first version in <https://bibisect.libreoffice.org/linux-64-5.4>). I didn't yet bother to check still older versions.
It also happens with OOo. But I don't understand why it should work in any other way. As I understand, the formatting apply to the selected text, it is not an option to stay selected.
(In reply to m_a_riosv from comment #1) > But I don't understand why it should work in any other way. > > As I understand, the formatting apply to the selected text, it is not an > option to stay selected. But why should the behavior be different depending on whether there's already any text present in the document (i.e., whether or not I execute step 2 of my reproducer in comment 0)?
Yes, it also does not get undone, if you start a new paragraph after the first one, activate Bold and click somewhere.