Same issue here, on most pages
Warning: file_put_contents(): Only -1 of 173 bytes written, possibly out of free disk space in /usr/local/emhttp/plugins/dynamix/include/DefaultPageLayout.php on line 714
As far as I can tell, it's not affecting anything else, no issues with plugin/updates. I've attached diagnostics as well.
root@Pantainos:~# df -h /
Filesystem Size Used Avail Use% Mounted on
rootfs 16G 2.2G 14G 14% /
pantainos-diagnostics-20230526-1105.zip