May be your Pi is still configured for old wifi’s ssid & password.
If this is the case, change ssid & password to the new wifi’s ssid & password.
You can edit wifi ssid & password by editing /boot/piaware-config.txt. This file is on the first partition of the sdcard and can be edited directly on a PC if you cannot SSH and running the Pi headless.
See https://flightaware.com/adsb/piaware/build/optional#wifi
pi@piaware:~$ sudo nano /boot/piaware-config.txt
…
…WIRELESS NETWORK CONFIGURATION
Should piaware use a wifi adaptor
for network access? You will need to attach
a supported USB wifi adaptor for this to work.
change this to “yes” to enable wifi
wireless-network yes
Wifi SSID and password.
This should be changed to match your wireless
network SSID and, for networks that require
a passphrase, the passphrase.
If your SSID or password contains characters other than
numbers and letters, such as the # character or whitespace,
you should enclose the value in quotation marks. For example,
“pass word” or “pass#word”.
To include quotation marks (") in a quoted value, use "
To include a backslash () in a quoted value, use \
wireless-ssid xxxxxxxxxxxxx
wireless-password yyyyyyyyyyyy
…
…