Hello! I'm sorry that issue still persists.
Please temporarily disable the firewall and see if the error still occurs. If it does not, then you can enable the firewall again and start allowing each blocked app one by one until you find the one that is causing the error. You can check the logs of your firewall software to see if it is blocking any specific Windows Store-related connections. some system processes, such as svchost.exe require internet access to function properly, so it's best to keep these unblocked if possible.
I hope it helps :)