In your router port forwarding settings, try changing the local IP to x.x.x.255 where the x.x.x. is the first three groups of your local IP. For example if your PC is 192.168.0.2 then set it to 192.168.0.255. The .255 tells the router to broadcast the magic packet rather than sending it to a particular IP. I know it shouldn’t be relevant but I got this to work in one of my networks I setup. However, recent routers these days seem to have disabled this feature (not allowing you to use .255, for security reasons). If this is the case, I have not found a working solution either - I gave up and switched to using a smart switch wired up to power switch jumper of the MB instead.

Hope this helped, good luck!