[BUG] Overriding with bold = false has no effect (while bold = true overrides)

[Galicarnax]

Describe the bug

In the default setup, function and method names are in bold, and I want then in normal font. I don't want to put bold = false in config, as I need bold in other parts. So I apply overriding:

      overrides = {
        ["@lsp.type.function"] = { bold = false },
        ["@lsp.type.method"] = { bold = false },
      }

but this has no effect. Yet, if I also override colors:

      overrides = {
        ["@lsp.type.function"] = { fg = "#8ec07c", bold = false },
        ["@lsp.type.method"] = { fg = "#8ec07c", bold = false },
      }

the color is overridden, but the boldness is not (still bold).
If I override the other way round, e.g.:

      overrides = {
        ["@lsp.mod.readonly"] = { bold = true },
      }

this works (constants in C++ become bold).

Expected behaviour

Highlight groups overridden with bold = false should not remain in bold.