I have found out what was causing the skipping through of 'Real-Debrid' (RD) Links in kodi, even if installed and setup correctly in 'URL Resolver' and the various addon's used.
If you use a VPN (any of them), some of the servers IP Addresses are blocked when accessing the RD servers at RD's end. This go's for use in Kodi and using the 'Real-Debrid' website for Torrenting / Downloading.
Initially when connected to your chosen VPN (e.g. uk123.ipvanish.com or uk123.nordvpn.com etc) go to:
https://real-debrid.com/vpn
and check to see if that particular VPN Server / IP Address is either Blocked, White Listed or Open.
They classify VPN Providers as either 'Co-operative' or 'Non Co-operative'. But even 'Non Co-operative' VPN Providers have links that work when using RD.
I have found that if you try connecting to several different VPN Servers individually, and refreshing the RD page link in your browser, you can see which VPN Servers are good to go.
Then just making a note of there status of the ones you are likely to use, you can always connect to one of these known servers in your VPN Software or Router.
The resetting of your Router as iv'e stated earlier is incidental as this just forces a re-connection of your VPN Server, and you might hit lucky on a 'White Listed' or 'Open' address.
I hope this makes sense as iv'e explained it.