Does that mean my internet is faulty or does that mean RM can't access internet?
The greyed out icon just means that RM can't access the Internet via your AV [Defender] and/or Firewall.
You can easily tell the difference, because if the Internet is visible to the Laptop [even if it isn't visible to RM], you should be able to navigate to any website using your browser. If you wrote your last post on the same Laptop as RM, then the Internet is working on it. RM is just being blocked from using it. At the end of the day, it should in theory only be a configuration issue in Defender / Firewall. It is just a case of finding out what needs to be set correctly and where the setting lies in what Windows screen.
Just for Information:
When I installed my copy of RM back in 2013 / 2014 [Windows 8 at that time, it is Windows 10 now though]. I ran the RM installer and the installer raised a pop-up asking a question along the lines of did I want to allow my Firewall (my Windows Firewall) to allow RailMaster. I answered 'Yes ... Allow' and that was it, the installer made all the necessary AV configuration changes for me and I did not have to do anything manually. It just worked, my Key activation went through OK at the first attempt and I got a Green Internet icon (yours being Grey). My AV application that was installed at the time and is still installed today [but version updated obviously] is ESET NOD32 and this AV uses the Windows Firewall, but it disables Windows Defender. I did not have to add any exceptions to my ESET NOD32 anti-virus either. It just all worked and configured itself on its own.
I appreciate that this not very comforting for you, but I only describe my experience so that you can see that it is not always normal to have to configure all these settings manually, Do you recall seeing the pop-up message that I described during your initial installation. If you did and you chose 'deny' instead of 'allow'. Then that would be your issue and some deep seated 'Windows Registry' flag has been set, that is now becoming difficult to recind.
I'm sure that you have seen and read it, but just in case you missed it or don't realise it is there. The RM installation places a 'Security.pdf' document file in the same place that the installation stored your RM manual. There is much guidance written in that document regarding creating exceptions. However, this PDF could really do with a Windows 10 re-write as it hasn't been updated for several years by HRMS.
This is where getting HRMS involved to log-on to your Laptop has sorted these issues out for others, they obviously know exactly where to go within the Windows security systems to manually make the necessary changes.