DSM 6.2.4025554 borked my inotify fix at boot.

[Akira]

It seems to have borked my run at startup task (it was working prior to this update as far as I was aware):

#!/bin/sh
 
# Update inotify.max_user_watches
echo fs.inotify.max_user_watches=524288 | tee -a /etc/sysctl.conf && sysctl -p

Checked this morning and it was still 8192.
Then I tried (to fix it now)
sudo echo fs.inotify.max_user_instances=1048576 > /etc/sysctl.conf
-sh: /etc/sysctl.conf: Permission denied

Any ideas what I've/is messed up?
Or how to check.
Most importantly, how to fix?

For the less technical reading this, I'm doing this to bypass a limitation to enable Jellyfin (Emby/Plex would also apply) in docker (and I believe Valheim uses it) to monitor file changes in real time.