Time to open app when connecting to local server

I’m running a local server on a Raspberry Pi. Everytime when opening the Blynk App on my Android smartphone it takes about 2 seconds until the connection is established. Within the 2 seconds I can see the three moving dots.
I’m just wondering wether this is a normal behavior. When connecting via the cloud server the app is responding instantly.
Sometimes it can be kind of annoying, for example if you just want to push a button.