Ts-231 unable to connect

[Dgoossens]

Hi,
I have a ts-231 (older.model) that has been running years without problems,
Since recently I often lose connection to the admin page, qmanager and also access from my kodi (nfs shares)
I do not see any errors on the device, so I wonder what might be causing the issue.
I removed all apps from it, besides the default ones.
When the nas becomes unreachable, ping is still working, so it does not get disconn from the network.
In a browser i usually see connection refused, but sometimes ERR_CONNECTION_FAILED
I already checked and it is not a duplicate ip issue.
Can anyone help please?