Selene is a chip to bridge between two NPU, which connects to GE interfaces each, and Metropolis, which in turn connects to the fabric. The error message indicates that the ingress low priority FIFO queue of the first Selene experience an ECC error. If there is only one ECC error, the linecard can correct the error. If there are multiple ECC errors on the same packet, the packet will be dropped and that refers to HW failure on the module.
1) Verify whether the Multi-bit errors are continued to be observed. If yes, you can proceed with re-seating the module and continue monitoring the performance.
2) If the problem re-surfaces back within the monitoring period, contact TAC to proceed with the RMA for the module replacement.
You can also find “DEV_SELENE” related errors on below link