L2STS circuit (TACC MASS) shows Active but passes zero L2 traffic

Hi,
The L2STS link between my TACC and MASS nodes on slice 50bc9a2f-d26a-4d9f-ae62-057ff62484ba has been dead for about a day now. It shows up as Active, but nothing actually goes across it. Ping shows 100% loss both ways and ARP never resolves, even though both interfaces are up with carrier and correct addressing. It was working fine yesterday, so something broke on the maintenance side maybe?

I have already spent time trying to fix it myself, like bounced the interfaces, re-added the IPs, flushed ARP , but still no change, and then deleted and re-added the whole L2STS, still forwards nothing. Meanwhile my four other L2STS links from the same TACC node (to DALL, CERN, TOKY, STAR) all work without any issue, so this is clearly isolated to the
TACC<->MASS circuit and not my VMs or config.

Can someone please look at the TACC-MASS dataplane path and tell me whether there’s a fault or maintenance going on?

Regards,
Sourya