Backlog limit exceeded, Ubuntu error

The Basics

  • Nextcloud Server version (e.g., 29.x.x):
    Diese Nextcloud ist auf Version 30.0.5
  • Operating system and version (e.g., Ubuntu 24.04):
    Ubuntu 24.04
  • Web server and version (e.g, Apache 2.4.25):
    Default installation of nextcloud while installing ubuntu
  • Reverse proxy and version _(e.g. nginx 1.27.2)
    Default installation of nextcloud while installing ubuntu
  • PHP version (e.g, 8.3):
    Default installation of nextcloud while installing ubuntu
  • Is this the first time you’ve seen this error? (Yes / No):
    no
  • When did this problem seem to first start?
    6 months ago
  • Installation method (e.g. AlO, NCP, Bare Metal/Archive, etc.)
    Default installation of nextcloud while installing ubuntu
  • Are you using CloudfIare, mod_security, or similar? (Yes / No)
    no

Summary of the issue you are facing:

I did an installation of ubuntu in a VM (Vmware) and was asked if I want to install Nextcloud. I said yes and migrated from ownloud to nextcloud.
Since that I have udated ubuntu as offered by ubuntu and nextcloud updated itself.

After one day of operation the screen is full of the message : backlog limit exceeded.

I have found nothing in this forum. I have followed steps proposes by copilot to change some entries in config files but that has changed nothing.
This is what I did:

sudo nano /etc/sysctl.conf
net.core.somaxconn = 1024
net.ipv4.tcp_max_syn_backlog = 2048
sudo sysctl -p

As the only thing that is running in this vm is nextcloud I was hoping that someone ran into that problem and has a solution for that.

Nextcloud is running fine for a couple of days with that message but eventually stops working and the VM needs a reboot.

In the nextcloud log there is nothing related to this ubuntu error message.

Steps to replicate it (hint: details matter!):

  1. restart ubuntu and wait for 1 day

(the first two entries in a search engine check that looked relevant)