Quill-mention not supporting existing format like bold italics, underline

[sahil-github101]

My Quill text after tagging is not getting bold even though the Bold option is selected. I am using quill-mentions for tagging operation.

import QuillMention from "quill-mention";

This is the sample that I am getting:

Hi @ABC how are you

Hi @abc how are you

and it should be Hi @abc how are you

The should be closed at the end but it gets closed whenever @ is pressed.

Mention Module:

allowedChars: /^[A-Za-z\s]*$/,
mentionDenotationChars: ["@"],
atValues: atValues,
source: function(searchTerm, renderList, mentionChar) {
  let values = mentionModule.atValues;
  if (searchTerm.length === 0) {
    renderList(values, searchTerm);
  } else {
    const matches = [];
    for (let i = 0; i < values.length; i++)
      if (~values[i].value.toLowerCase().indexOf(searchTerm.toLowerCase()))
        matches.push(values[i]);
    renderList(matches, searchTerm);
  }
},

};

Any context on how to use parchments for this?
I tried:
var Parchment = Quill.import("parchment");
config = {
scope: Parchment.Scope.INLINE
};
var formatAttributor = new Parchment.Attributor.Class("bold", "ql", config);
Quill.register(formatAttributor);

but didnt work

Current Bold format:

import Inline from "../blots/inline";

class Bold extends Inline {
static create() {
return super.create();
}

static formats() {
return true;
}

optimize(context) {
super.optimize(context);
if (this.domNode.tagName !== this.statics.tagName[0]) {
this.replaceWith(this.statics.blotName);
}
}
}
Bold.blotName = "bold";
Bold.tagName = ["STRONG", "B"];

export default Bold;