MacBook Pro (2018) stopped detecting external monitor

My new MacBook Pro suddenly stopped recognizing external monitor (Dell U2515H) after 2 days of normal usage.

Yesterday, after I was done with my work, I closed the lid as usual and today, I opened the MacBook and the external monitor didn't get detected.

The monitor is connected via USB-C -> HDMI cable (cost about 20$).

I have already tried restarting my mac, reconnecting the monitor and detect monitors in system preferences.
I have also tried reseting SMC and NVRAM. Unfortunately none of it worked.

Detailed info:

• MacBook Pro (2018) – 15", i7
• Mac OS High Sierra – 10.13.6
• USB-C to HDMI cable
• Monitor: Dell U2515H

Any help is highly appreciated as I really need my external monitor for work.