Modem is only talking IPv6; no IPv4.

I support an office where the cable modem is only communicating via IPv6 on both the WLAN and LAN interfaces and we cannot access certain websites. Unfortunately, one of those sites is the physician’s Electronic Health Record system which he's expecting to use next week.

I restarted the modem through the online account management page, I manually recycled the power, and I reset it to factory default via the reset button.  The issue persists. 

I cannot connect to the 10.1.10.1 management page on account of that being an IPv4 address, so I can’t check the device’s settings. Phone support was not helpful; all three of calls to them were dropped each time the tech was supposedly transferring me to someone who could help.

Is there an alternate method of accessing the modem’s management page, or is there a direct line to higher level of tech support so I can speak to someone who may be able to help?