1. Adding CPT (e.g. Portfolio). Only slug and publish. Default setting. — It's work.
2. Adding Post to Portfolio. Only Title and publish. — It's also ok.
3. Then I trying to change «Custom archive slug» (e.g. Projects) in Advanced tab — doesn't work. Permalink has default slug Portfolio in this case. «Has archive» is on.
If I change «Custom rewrite slug» option both permalinks changing. Archive and Post.
Permalinks setting in «Settings > Permalinks» also re-save after make changes.
Make clean install of WordPress — same trouble.
No caching plugin installed.
Metabox and Metabox AIO — latest versions.
With CPT UI plugin at the same WordPress install everything works as expected without problem.
It feels like I'm doing something wrong… or not 😅
Thanks for advice.