Not sure if this generalizes, but sharing my data point in case it helps. I updated both the iPhone and Apple Watch to 26.6 and the install started working again. Before that, I'd tried an intermediate state — Watch on watchOS 26.6, iPhone still on iOS 26.5.2 — and it still failed with the same error (ACXErrorDomain Code=8 "Failed to create socket" / Socket open timed out, same ~64s timeout every time). So at least in my case, updating just one side wasn't enough — both needed to be on 26.6. Tested with a minimal test project and our own enterprise-signed app, both installed fine afterward. Could be coincidence, or could be tied to something else in my setup (I'd also just re-paired the watch beforehand, though that alone didn't fix it). Curious if it holds for others on 26.6.