Create a new Calc sheet, enter 1, 2 and 3 in cells A1, A2 and A3. Select cell A4. Now press Ctrl-F and type 2 and click on Find Previous. Cell A2 is selected. Press Ctrl-C. Now click on an empty cell in the sheet, and press Ctrl-V: nothing is pasted (or whatever you had saved in your clipboard from before). It seems you need to explicitly click on the cell itself after running find, in order to successfully copy this cell. I'm using the Libreoffice 25.8.0~rc4-2 Debian packages on Debian Sid.
Needs to get the focus out of the Find bar.
Already in oldest of linux-43all repo. When using the buttons immediately after inputting something to the find field, the focus indeed seems to be in an unknown place. When you already have something in the field, click somewhere in the cells and then click a find button, the focus does go to the found cell (at least most of the time?!).
Same is true for other actions but not all, bold/italic works but underline not. I can change the cell background but not undo per shortcut. Copy via the main menu works. I remember Caolan did some kind of similar solution in the past. This might be a duplicate of bug 70883