Intermittent 523 errors, cannot find any issues on my network

Hi I am struggling with intermittent 523 errors when connecting into my homelab. I have done lots of investigation on my home network and have found nothing that seems to be happening when I cant connect then suddenly it just starts to work, this has been working well for many months and I am not sure what could have caused this to start happening

https://navidrome.wrightbennett.co.uk/ is an example URL