Are you saying you bought a new WM100 and new router and you still can't connect to the server? And that your other WiFi devices, like your phone, can connect to the internet using WiFi?
If yes to both it sounds like the X10 server may be down and hopefully another user here will chime in. Have you called X10 Customer Service to ask them? They might be able to help.
This is where I always make my pitch to replace the WM100 with a far better product.
If you're having problems with the WM100 I'd like to suggest you return the new one to Amazon and spend just half that money for a Smartenit Harmony P2 and get everything the WM100 does plus Alexa/Google Home integration, real time clock and more.
As an almost 40 year user of X10 I was thrilled to be able to control my system with Alexa using a simple plug'n' play device that can also function as a full blown X10 controller.
The solution I'm using is a Smartenit Harmony P2 with a bundled Insteon 2412UPLM. At $60 for
both it's an economical solution that not only gives you Alexa skill supported control of X10 but an app and a sophisticated automation controller with email and text notifications. I've been using it for almost 3 years and it's rock solid. It's basically what X10's WM100 should have been but for half the price and better functionality. It's virtually plug 'n play so you can be up and running 30 minutes after you open the box. Everything is done through an Android/IOS app or web portal. In addition to X10, you can also use it to control Insteon and ZigBee devices should you ever wish to.
https://smartenit.com/shop/zigbee-insteon-x10-multi-protocol-gateway-hub/If you order be sure to click the selection to include the 'Add Insteon/X10 powerline only PLM.' bringing the total to $59.99.
Feel free to ask any questions. A growing number of us here are using the P2 successfully.