To start, you have an invalid frontamatter (check for error message)… I guess you need to quote a code, if not it’s considered an invalid symbol.
For now, preview mode isn’t a reliable for inline queries.
Inline queries as values aren’t a good choice (because they work well only inside the current file, not for external queries… why? because the real value is =the inline code, not the outputted value. if you get the value =this.file.name in a table query placed in another file, this means the current note, not the original one)
EDIT: Ignore my post. I just misread your goal (I thought you’re trying to build a frontmatter with inline queries). @eightning is right: only implicit fields needs the prefix file.; custom fields are page level fields, without prefix.
There was something wrong with Obisidan app. All solutions does’t help me to get rid of the “-” output. I disabled all plugins, restarted Obsidian app, enable the plugins and then all works like charm.
@mnvwvnm Thank you for explaining me the difference between the custom class and standard classes of YAML fields.