It's in router mode, and it seems to THINK it has IPv6, but I don't see that outside my network consistently with https://ifconfig.co/ or https://test-ipv6.com/
My network IT contact in the office swears that he had the same issue with the modem seeming to have IPv4 and v6 addresses, but not behaving as expected since the middle of last week, and it was fixed with the full stack change.
I'm not in DS lite mode, and I wouldn't say the router is set with IPv4 only but it seems to behave like it is
I noticed that the modem reset and came up Wednesday morning, as the log entries coincide with about the May be coincidence, but I was able to use Citrix Tuesday evening.
The WAN screenshot below is from Friday - when I started responding, but failed to submit it. I was
05:21:07 5 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=e4:57:40:f9:92:26;CMTS-MAC=00:17:10:91:60:95;CM-QOS=1.1;CM-VER=3.1;
05:18:15 6 SW download Successful - Via NMS
05:16:48 6 SW Download INIT - Via NMS