DIAGNOSIS The soundbar's wireless module has likely glitched or saved an old network credential that's no longer working. It's a common hiccup after a router update or password change.
FIX We need to clear the old network info and start fresh. 1) On the remote, press the Home button. 2) Go to 'Settings' > 'Network Settings' > 'Network Setup'. 3) Select 'Set up network connection' and choose 'Wireless'. When it shows the list of networks, highlight your network but DO NOT select it yet. Instead, press the Options button on your remote (the one with three dots). 4) A menu will pop up. Select 'Clear network settings'. Confirm. Now, go back and select your network fresh, entering your password carefully.
IF THAT DIDN'T WORK Your router might be using a wireless band (like 5GHz only) or security setting (like WPA3) that the soundbar struggles with. Temporarily change your router's 2.4GHz network name (SSID) to something simple, like 'TestNetwork', with no password, and see if the soundbar can connect to that. If it can, the issue is with your main network's configuration.
HEADS UP The HT-A7000 can be fussy with mesh Wi-Fi systems where the 2.4GHz and 5GHz networks share the same name. If you have a mesh system, try temporarily disabling the 'band steering' feature in your router's app and connecting the soundbar to the explicit 2.4GHz network.