To be clear, you are saying that after a chain has been created with Chain Affinity and you close that with Expi that a subsequent ws will not extend the sc to create a new sc?
Ex: swift blade > heavy strike (fragmentation) > Expiacion (Distortion) > Evisceration (Darkness).
You're saying that the chaining process fails at Expiacion to Evisceration (Darkness)?
This would be an example of a planned skillchain that used to work, but now would break at the usage of Expiacion in this order, assuming someone other than the BLU did it.
The discovery came from this skillchain:
Immanence Aero > Immanence Noctohelix (Gravitation) > Chain Affinity Barbed Crescent (Darkness) > Wildfire (Darkness)
This skillchain used to work, when tested this week the Wildfire no longer creates Darkness after the Barbed Crescent Darkness. A small note, in your Japanese forum post, you changed the Solo or Party note to say Solo or Party, when the English forum post states it is Party only. The behavior of a BLU being able to extend the skillchain after their Chain Affinity may be something we didn't test, but the important issue here is your example skillchain, and my example skillchain no longer working when a player other than the BLU attempts to extend it.