paintEvent not being called in custom widget

I am trying to paint a rectangle at the mouse location every time it is clicked.

Currently, the setup is as follows:

TableMaker is my main window and was mostly generated in Qt Designer.

I have subclassed a QWidget, RenderArea, and added it inside a frame in my ui.

I currently have TableMaker::mousePressEvent calling a function in renderArea that creates a new QRect and keeps a reference to it in a vector.

So far everything up to this point works, and when I check in a debugger it is indeed creating these QRects and storing them on each mouse press.

However, I tried overriding paintEvent for renderArea so that it will update and draw these new QRects, but it is never being called.

I feel like I have misunderstood how painting and the associated events work, and who should actually have ownership of the overridden paintEvent.

Below is the code for the 2 classes TableMaker and RenderArea:

main.cpp:

#include "TableMaker.h"#include <QtWidgets/QApplication>int main(int argc, char *argv[]){    QApplication a(argc, argv);    TableMaker w;    w.show();    return a.exec();}

TableMaker.cpp:

#include "TableMaker.h"TableMaker::TableMaker(QWidget *parent) : QMainWindow(parent){    ui.setupUi(this);    renderArea = new RenderArea;    QGridLayout* drawAreaLayout = new QGridLayout;    drawAreaLayout->addWidget(renderArea);    ui.tentFrame->setLayout(drawAreaLayout);}void TableMaker::mousePressEvent(QMouseEvent* e) {    renderArea->addNewTable(e->pos());    renderArea->update();}TableMaker::~TableMaker(){}

TableMaker.h:

#include <QtWidgets/QMainWindow>#include <QtWidgets>#include <QtGui>#include "ui_TableMaker.h"#include "RenderArea.h"class TableMaker : public QMainWindow{    Q_OBJECTpublic:    TableMaker(QWidget *parent = nullptr);    void mousePressEvent(QMouseEvent* e) override;    ~TableMaker();private:    RenderArea* renderArea;    QLabel* statusMsg = new QLabel;    Ui::TableMakerClass ui;};

renderArea.cpp:

#include "RenderArea.h"RenderArea::RenderArea(QWidget* parent): QWidget(parent) {    brush.setColor(tableColor);    pen.setBrush(brush);}void RenderArea::addNewTable(QPoint p) {    QRect* rec = new QRect(p, QSize(100, 100));    recs.push_back(rec);    this->update();}QSize RenderArea::sizeHint() const {    return QSize(100, 100);}void RenderArea::paintEvent(QPaintEvent* e) {    QWidget::paintEvent(e);    QPainter p(this);    p.setPen(pen);    p.setBrush(brush);    for (QRect* r : recs) {        p.drawRect(*r);    }}

renderArea.h:

#include <Qtwidgets>#include "tableWidget.h"class RenderArea : public QWidget {    Q_OBJECTpublic:    explicit RenderArea(QWidget* parent = nullptr);    void addNewTable(QPoint p);protected:    QSize sizeHint() const override;    void paintEvent(QPaintEvent* e) override;private:    QColor tableColor = QColor(0, 0, 255);    QBrush brush;    QPen pen;    QVector<QRect*> recs;};

How do paintEvents / painting work? I have tried reading the docs about QPaintEvent and it seems like I am overriding paintevent correctly.

Another post on here mentions that sizeHint must be reimplemented, but as you can see below, I have done that and it still does not work.