I would also add that sometimes it is rather dependent on whether you have layout “Inner blocks use content width” switch on or off.
But in general, I asked about the logic of showing/hiding width settings for the blocks and it turned out that there’s a deep (but I would personally say “strange”) logic behind that so it is a feature of Gutenberg when you got this option shown or not totally unpredictable.
@solarian-ian You could try posting in your theme’s forum. Be sure to provide a link to your site so folks can take a look directly. I’m still not sure which block you’re not seeing alignment options for. ??
In a Header part template of a block theme, you can group a logo, a site title and a navigation. this group parent of logo, site title and navigation has no align optios.