vga splitter can't push out two display from apple VGA adapter

I bought an apple VGA multi adapter together with MBP 2017.

The dual display mirror well to my 15" Dell monitor. So far so good until I attempt to further connect it to a VGA splitter.

Why I do that? Reason is this, I am a trainer uses lots of Powerpoint to do presentation. What I want is , I would love to have my display on my MBP to display some notes (hidden from the students), then project out slides to the projector at the same time to an external monitor . So to do this, I connect the Apple VGA multi adapter to a splitter so that it will then push the extended display to both projector and monitor. So far it manages to extend display to the projector, but nothing shown on external monitor. So far I have changed 2-3 monitors, but fail. I reckon the adapter do not have sufficient power to push the display.

OR does anyone knows what and how to fix this?

Regards

Jason W

whatsapp +6012.273.6143

email : jasonwcc@yahoo.com