Level3 (3356) to outlook.office365.com via v6?

Curious if anyone else is having issues reaching outlook.office365.com via ipv6 over Level 3? Our customers have begun reporting failures checking email, and in the ones who have had this issue, are using the mail server name outlook.office365.com and are on v6. Traceroute6 shows the traffic dying shortly into Level 3 land at 2001:1900:4:1::3d1 which is likely a Tampa-area router.



We have 2 customers complaining about this in the past 3 days - both using IPv4 only. Glad to see this because maybe it’s a larger problem outside of our network.