Well, you are not a newb so you should have seen similar “Local Server upgrade issues” around the forum 
New versions of Blynk Server (and Cloud for that matter) use port 9443 in the App and 8080 (TCP) 9443 (SSL) on the hardware device
Don’t forget to update your Library as well before flashing… all Blynk components (App, Server & Library) need to be kept keep in version sync with each other over time.
The ports as per the various Announcements…
And if you are using SSL… there may be some other script changes needed… here is another very recent post about such…