how can a change the protection of a group of cell if some are protected and some not

If I un-protect a cell in calc and then select a block of cell containing this cell with other that are protected I cannot change the protection to be the same for all cells it the block. The tick box shows “-” and I can’t change this.
I am wondering if this a bug as I found I could solve it with Oo.

Are you aware of the fact that you cannot edit cell attributes for protected cells as long as the sheet is protected?

By other question of “@petera1”, I suppose that the issue is with LO 6.2 on Ubuntu.

No problem in LibreOffice (x86); OS: Windows 6.1.

@Lupp, menu Format - Cells… (same as Ctrl+1) is disabled while the sheet is protected.