We are running UFM 4.5 but that runs opensm underneath which is version 3.3.13. We are using SX6025 switches. We are not running the latest firmware on the switches - its version 9.2.3.
So perhaps the issue is with the switch or the opensm configuration? I went to reduce the opensm sweep time but it was already at the lowest value that UFM would accept - 10 seconds.