How to mock static method in Junit 5?

Question

I tried with mockito-inline and it doesn't work in my case.

Class BankService {

    //BankService will autowire 2 repositories, say bankRepo and fundRepo;

    public Fund onMessage(Object obj){
        Processor processor = ProcessorFactory.getProcessor(obj.getAccountType());
        processor.process(obj);
        //rest of logic
    }
}

Class ProcessorFactory {
    public Processor getProcessor(String accountType){
        switch(accountType) {
            case "A": return new AProcessor();
            case "B": return new BProcessor();
            //rest of the logic, simple switch
        }
    }
}

@ExtendsWith(MockitoExtension.class)
Class BankTest {
    
    @Mock
    BankRepository bankRepo;

    @Mock
    Aprocessor mockProcessor;

    @Mock
    FundRepository fundRepo;


    @InjectMock
    BankService bankService;

    @Test
    public void onMessage(){
        when(bankRepo)...
        when(fundRepo)...
        //Now how can I mock ProcessorFactory in bankService?
        try(MockStatic mock = mockStatic(ProcessorFactory.class)) {

           //Strangely the assertThat statement passed, so it means it does return a mockProcessor.
           when(() -> ProcessorFactory.getProcessor(any())).thenReturn(mockProcessor);
           assertThat(ProcessorFactory.getProcessor(any())).isEqualTo(mockProcessor);
           
           //However, when onMessage is called, ProcessorFactory.getProcessor return an actual object, not mockProcessor
           bankService.onMessage(obj);
        }
    }

}

I know junit4 has powermock and prepareForTest and I've done static mocking before in junit4. However for this project, I can only use junit5, and I can't change the code.

If I don't have a mock object returned from ProcessorFactory, it will be very difficult to test because these processors calls many other services and db operations. I know it is not ideal, but that is what I have.

Any help will be appreciated. Thanks in advance.