QSortFilterProxyModel search and view scroll help

I have a QSqlTableModel and a QTableView. Trying to sort through the model, find a record, then scroll to it in the view.
Here is the code, where strID is a string to search for, like "89".

Code:

---

QSortFilterProxyModel proxy;
proxy.setSourceModel(model);
QModelIndex vidx;
 
proxy.setFilterKeyColumn(0);
proxy.setFilterFixedString(strID);
vidx = proxy.mapToSource(proxy.index(0, 0));
 
if (vidx.isValid())
{
	view->selectionModel()->select(vidx, QItemSelectionModel::Select | QItemSelectionModel::Rows);
	view->scrollTo(vidx, QAbstractItemView::EnsureVisible);
}

---

I am having two problems.

1. If the header sort is set to column 0 ascending, and the record found has a sequential value in column 0 of more than 256, the scrollTo does not work, 256 or less and it works fine.

2. if the header sort is set to column 0 descending, and the record found has a sequential value in column 0 of 89 for example, the view scrolls to the record with 289 in column 0.

Any advice as to how to overcome these problems greatly appreciated.

Didn't seem to be able to edit this post.

Here is the update: problem number 2 has been solved with the following code:

Code:

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proxy.setFilterKeyColumn(0);
 QRegExp exp("^"+lastID+"$");
 proxy.setFilterRegExp(exp);

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It now matches only the whole string. Some success.

No luck with problem number 1. QSortFilterProxyModel does not seem to work with a record more than 256 rows down from the top, no matter how the view is sorted. vidx comes back invalid in those cases. No idea why.

Come on experts, I need some help here! Anyone else having this problem?
Thanks for any advice.