Gave my self a perm thats increased. Usually i relog and it works but i had to reload the plugin in this case

The Backpacks plugin utilizes hooks to detect when permissions change, in order to basically instantly resize backpacks. This has always worked in my testing, so not sure what's happening on your end. If you download the pre-release of the plugin from the GitHub repo (linked on the sidebar of the plugin main page), that version has a debug command you can do to help troubleshoot the size, something like `backpacks.debug.size <player>`.