With the newest iOS 12 compatible version 1.600.19 of capsule connect "sending" actions are very slow (at least 10 times slower than on iOS 11 with old version of capsule connect).
We have an iOS app which communicates with an server via REST services (http requests via NSUrlConnection); the transfer of a bigger amount of data from the app to the server is now very slow, whereas the data transfer from server to app is as quick as usual.
I tested the same both on iOS 11 devices with old capsule connect and on iOS 12 devices with new capsule connect and also with a connection to a server which requires VPN and one which do not need VPN.
Only in case of iOS 12 with new capsule connect and connection to a server which requires VPN the very slow "sending data transfer" happens.