If following TechnicallyWell's instructions doesn't work maybe this can shed some light:
Here's a quote from PCWorld regarding HP and its USB-C charging.
"It still won’t work with third-party chargers. Here’s why.
After speaking with HP officials about the issue, it appears the company is just playing it safe. Fearing that a counterfeit or out-of-spec charger could make the touchscreen or audio subsystem flaky, HP has limited the access non-certified chargers have to the device. For now, HP exec Mike Nash told us, only “overnight” charging, or charging while the device is off, is supported.
”Are we being too conservative?” Nash asked. “I don’t think so.”