Output 4k at 60hz with Dell P2715Q MBP 2017

I am unable to output 4k at 60hz (only 30hz) with my 2017 MacBook Pro using

1. Dell P2715Q 4k Monitor

2. Apple Multiport Adapter

3. Compatible HDMI Cable

4. 2017 Macbook Pro

I have tried changing the Dell monitor to HDMI 2.0 by turning off HDMI 1.4, and the monitor was purchased after February 2016 so it should be compatible. However, this did not work.

According to Apple, it should work "With macOS 10.12 or later, MacBook (2015 and later) and MacBook Pro (2016 and later) support these resolutions and refresh rates over HDMI 1.4b using the USB-C Digital AV Multiport Adapter:

• 4096x2304 at 48Hz refresh rate
• 3840x2160 at 60Hz refresh rate (mirroring is not supported at this resolution)"

(Using 4K displays, 5K displays, and Ultra HD TVs with your Mac - Apple Support).

Has anyone made this setup work? Do I have to use a DP cable to get 4k at 60hz?

Thanks!