Hi @TrystanLea , please don’t be sorry, you’re so nice to consider my issue 
I do see data on graphs and dashboards, it works. All the IotaWatts which are connected are visible in those data, and data is uptodate.
The system is a Debian server (not raspberry):
Debian GNU/Linux 10 (buster)
Server version: Apache/2.4.38 (Debian)
PHP 8.0.13 (cli) (built: Nov 22 2021 09:48:13) ( NTS )
mariadb Ver 15.1 Distrib 10.3.31-MariaDB, for debian-linux-gnu (x86_64) using readline 5.2
Redis server v=5.0.14 sha=00000000:0 malloc=jemalloc-5.1.0 bits=64 build=ddd3b1f304a7d4d5
CPU: 4.19.0-18-amd64
x86_64
We configured it ourselves, and it worked up to now (even if we had some server load issues in the past that you helped to solve: High server load - #18 by sisim - since then, we upgraded the hardware and everything was working fine).
The current issue might also be related to an update of the system, which went to PHP 8.1. After this update, Emoncms wasn’t working anymore, so I updated emoncms (git pull origin master, currently 10.9.19). It was still not working, so I removed PHP 8.1 and reinstalled PHP 8.0 (currently 8.0.13). Then emoncms is working again, except the feed page.
There was probably something broken in those changes. What I don’t understand, is that all other applications on the server, also using PHP, don’t have any issue (Nextcloud, OnlyOffice, Wallabag, Mattermost, …).