I recently purchased a Bery AX router and I'm having the same issue. I'm trying to use a xiaomi 65w PD gan charger, and it does not power the router. I've tried different cables with the same result. Oddly, if i plug and unplug the router repeatedly, sometimes it seems to work, about 1/10 the time. When it negotiates power, it works perfectly fine.
Please check the charger specs attachment.
Do your routers include the 5.1k pull down resistors on the cc pin?