not able to filter minute using matDatepickerFilter

[dass80056]

this is my html code

Start DateTime
<input matInput formControlName="startDate" [matDatetimepicker]="dts" required autocomplete="false" [matDatepickerFilter]="dateFilter">
<mat-datetimepicker-toggle [for]="dts" matSuffix>
<mat-datetimepicker #dts type="datetime" openOnFocus="true" timeInterval="5">

ts file:
dateFilter = (d: Date): boolean => {
let date= d.getMinutes();
return date ==0 || date ==30;
}

I want to just enable the 00 and 30 minute option.
here when the minute comes up then In the UI it shown as disable but when I click using mouse on the disabled minute then it takes that minute in the input.

It seems like matDatepickerFilter is only working properly till the day filtering when it comes to timing it is not compatible.