Core switch reboot was performed 01.30 – 01.35 due to memory leak (stack bug).
A tentative fix is the reboot and to avoid causing the ACL conflict which led to the memory leak.
At 04.00 – 04.05 another test was made to replicate the issue. The issue has most likely been found and a new fix has been applied.
Longterm solution will be to replace this switch line with new core routers , Juniper MX204.