blazor editform and submit buttons with an @onclick

In my Blazor Webassembly app, I have an EditForm with two submit buttons.

Each of the submit buttons has an @onclick handler which just sets a model value so I can tell which button was pressed.

This works fine under .Net 6 and 7, the value is set and validation and submit processing proceed as usual.

Under .Net 8, the @onclick hander is called, but validation and submit do not.

Any suggestions?

I have also tried calling EditForm.EditContext.Validate in my @onclick handlers. this returns false when there are validation errors (as expected) but no error messages are displayed.