Column Header disappears when showing only weekdays with weekendButton

[taauntik]

Forum post

Reproducible here https://codepen.io/dv-auntik/pen/jEEporz?editors=0010

    modes : {
        week: {
            maxAllDayHeight: '100%',
            allDayEvents: { autoHeight: true },
            columnHeaderRenderer: (dayCell) => {
                let count = dayCell.events.length;
                dayCell.view.calendar.eventStore.records.forEach(record => {
                    if (DateHelper.betweenLesser(dayCell.date, record.startDate, record.endDate) && record.allDay) {
                        count++;
                    }
                });
                return `${count}`;
            },
        }
    },
    includeWeekendsButton : true,