Hi Hans.
After repeated testing over the weekend with replaced cables, with just the Dragonfly app open and reading the log and SGP open with Dragonfly connected (SGP 4 and 3) the network disconnects have persisted. So I have no evidence that my problem is related in anyway to SGP; indeed everything indicates a problem with my ver1 Dragonfly.
Jaime and Andy at Lunatico Astronomia have responded very promptly to my support request and I am returning the Dragonfly to Lunatico for repair.
Hope that helps.
Barry