詳細行にグリッドを設定します。
この時、親グリッドの１列目を非表示にすると詳細行内のグリッドが表示されません。

この問題はバージョン5.20242.21で修正されました。

修正版を適用しない場合の回避方法は次の通りです。

_renderCellメソッドを以下のように書き換えます。

import { createElement, setAttribute, toggleClass } from '@grapecity/wijmo';
import { _NewRowTemplate, GridPanel, _SelectionHandler, CellType, SelectedState } from '@grapecity/wijmo.grid';

GridPanel.prototype._renderCell = function (e, t, i, o, n, r) {
  var l = this._g
    , s = l.getMergedRange(this, t, i, !1);
  if (s) {
    for (var a = Math.max(o.row, s.row); a < t; a++)
      if (this.rows[a].renderSize) return r;
    for (a = Math.max(o.col, s.col); a < i; a++)
      if (this.columns[a].renderSize) return r;
    if (t >= s.row && t <= s.row2 && i > s.col && i <= s.col2 && this._ct === CellType.Cell && s.isSingleCell) return r;
    var u = this.columns.frozen;
    if (u && s.col < u && s.col2 >= u && i > s.col) return r;
    if (s.leftCol != i) {
      if (this._ct != CellType.ColumnHeader && this._ct != CellType.TopLeft) return r;
      for (var c = s.leftCol; c < i; c++)
        if (this.columns[c].isVisible) return r
    }
  }
  var d = this.columns[i];
  if ((!d || d.renderSize <= 0) && (!s || s.getRenderSize(this)
    .width <= 0)) return r;
  var h = e.children[r];
  if (h && !n && this._recycle && l._lazyRender && !l.activeEditor) {
    var p = h[GridPanel._INDEX_KEY];
    p && p.row == t && p.col == i && p.rng == s && t >= this.rows.frozen && i >= this.columns.frozen && (n = !0)
  }
  var f = SelectedState
    , g = this.getSelectedState(t, i, s)
    , _ = g == f.Cursor || g == f.Active
    , m = !1;
  switch (this.cellType) {
    case CellType.RowHeader:
    case CellType.ColumnHeader:
    case CellType.TopLeft:
      m = !0
  }
  if (h && n) {
    toggleClass(h, "wj-state-active", _);
    toggleClass(h, m ? "wj-focus-header-cell" : "wj-state-selected", g == f.Cursor);
    toggleClass(h, "wj-state-multi-selected", g == f.Selected);
    var C = h.querySelector(".wj-column-selector");
    C ? _ || g != f.None ? setAttribute(h, "aria-selected", !!C.checked) : setAttribute(h, "aria-selected", null) : setAttribute(h, "aria-selected", !(!_ && g == f.None) || null);
    _ && (this._activeCell = h);
  return r + 1
  }
  h || (h = createElement(GridPanel._HTML_CELL, e));
  setAttribute(h, "aria-colindex", i + 1);
  _ && (this._activeCell = h);
  if (this._ct == CellType.Cell) {
    setAttribute(h, "role", "gridcell");
    setAttribute(h, "aria-selected", !(g == f.None && !_) || null);
    var w = !l.canEditCell(t, i) || null;
    setAttribute(h, "aria-readonly", w);
    setAttribute(h, "aria-required", w ? null : d.getIsRequired())
  }
  l.cellFactory.updateCell(this, t, i, h, s);
  h[GridPanel._INDEX_KEY] = {
    row: t
    , col: i
    , rng: s
    , panel: this
  };
  return r + 1
};