We have a number of new 400G provider waves with odd flakiness that we can't seem to sort out. These links appear good - light levels are fine, links will be up with working LLDP. But if we admin down / up the link on the IP side, many of them won't come back up on their own. Our provider sees "loss of alignment" alarms on the optical equipment, and we can eventually get the links back up if they bounce them a few times on the DWDM side. We're using Juniper PTX's, with Juniper 400G FR4 and 400G LR4 optics. Same issue on different circuits/devices/paths with this provider, but no issues with other transport providers using the same optics on our end. Believe our provider is using Ciena optical equipment. Has anyone seen issues like this before? Our provider has been looking into this for months without much progress. One tantalizing clue was another customer using Cisco Nexus had better results after they enabled "link transmit reset-skip" (https://quickview.cloudapps.cisco.com/quickview/bug/CSCvi45168). Not clear exactly what that option does, and there doesn't seem to be an obviously equivalent config knob in Junos. Thanks, Oliver