Search field in filter of a custom column in the Release AP Documents not working in Modern UI

Hello Team!

I have a customization for the Release AP Documents form that adds a couple of fields to the grid (Cash Account and Cash Discount Date).

On classic UI the column filter works ok for the Cash Account. But with modern UI, the search field of the filter wont list the available cash accounts:

This is my custom TS extension:

import {
  PXFieldState,
  columnConfig,
  GridColumnDisplayMode
} from "client-controls";
import { AP501000, APRegister } from "src/screens/AP/AP501000/AP501000";

export interface AP501000_CBAPReleaseImproved_generated extends AP501000 {}
export class AP501000_CBAPReleaseImproved_generated {}

export interface APRegister_CBAPReleaseImproved_generated extends APRegister {}
export class APRegister_CBAPReleaseImproved_generated {

  @columnConfig({ allowFilter: true, width: 100, visible: true, allowUpdate: false, hideViewLink: true, displayMode: GridColumnDisplayMode.Both })
  APInvoice__PayAccountID: PXFieldState;

  @columnConfig({ width: 100, visible: true })
  APInvoice__DiscDate: PXFieldState;
}

So far no columConfig attribute seems to maje it work. 

I don’t know. Is it a modern UI bug?