@myrddin55
This might sound like a stupid question, but WHY are you using loads of port forwarding rules with a NAS ?
Inside your LAN you SHOULD be able to access it just using the NAS's network HOSTNAME or using a fully qualified domain name(s) - (for example 'nas.myrddin55.plus.com' or 'synology.myrddin55.plus.com'), or using it's LAN IP address.
To access your NAS remotely from elsewhere on the internet, you should be using the built-in VPN server 'package', and then ONLY forward the relevant VPN ports (e.g. UDP 1194 for OpenVPN, or UDP 500, 1701, 4500 for IPSec VPN).
Similarly there appears to be some sort of "Mobile application" which ONLY requires TCP ports 5000 and 5001 forwarded.
You should NEVER allow other port forwards from the WAN to LAN to access a NAS - you are inviting hackers to access your files - as they will have unlimited attempts at brute force attacking your login details !. Earlier today in an answer to somebody else, I checked MY home network firewall, and could see that hackers were port probing my connection at a rate of FIVE attacks per SECOND and my connection is invisible from the internet (so they don't know that anything is there), the rate of attack would be much higher if ANY of my network ports were visible because of unnecessary port forwards.
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