Dear friend!
Yes, the UXCMS board of the OSN 1800 V supports 1+1 backup. Generally, the switchover of the UXCMS does not cause the restart of other service processing boards. If the PCM board restarts or even services are interrupted during the switchover of the UXCMS board, it indicates that an exception occurs.
If only the PCM board is affected, check the PCM board. If all service boards on the NE are affected, check whether the boards are securely installed and whether the software versions of the active and standby UXCMS boards are the same.
If no root cause is found, please collect device data and submit it to Huawei TAC engineers for analysis and fault location.
Thank you!