Hi James, I feel your pain—LACP issues can be incredibly frustrating, especially after updates that were supposed to improve things! It sounds like you’ve got a pretty complex setup with the MS425s and MS350, which can definitely introduce more variables. I've also run into similar issues with LACP and spanning tree configurations in the past. One thing that helped was double-checking all configurations on both ends of the links to ensure they match up perfectly. Sometimes the smallest mismatch can lead to these looping problems. Have you considered temporarily disabling Loop Guard to see if that changes the behavior? It might help clarify if that's where the issue lies. Additionally, keeping a close eye on the logs for any STP messages might give you more insight into why it’s detecting loops. I hope you find a solution soon—these intermittent issues are the worst! If I come across anything else that might help, I’ll let you know. Good luck! ... View more