Hello,
Please provide a more detailed explanation of the issue? What device/firmware are you using?
Could you try enabling the following: login to the router's WebUI, navigate to Network -> Firewall -> General settings and set Software flow offloading slider button to on.
Preferably, I would like you to attach a troubleshoot file.
To generate the file, access router's WebUI, go to System -> Administration -> Troubleshoot section and download troubleshoot file from there. The logs in the file might provide more insight into the issue.
Best regards,
