This was working fine previous to this months wipe.

the backpacks are dropping from the players regardless of config and regardless of permission.

I'm not able to reproduce this issue. I have "Drop on Death (true/false)": false in the config/Backpacks.json on my test server and I am keeping my backpack when dying. I haven't granted the keepondeath permission.

My first thought is that maybe your config has incorrect syntax, which would cause the plugin to apply the default config at runtime. However, if that were the case, granting the keepondeath permission would still prevent backpacks from dropping. I'm guessing that when you said "regardless of permission" that you meant you already tried that.

It is possible that another plugin is calling the Backpacks API (API_DropBackpack) to explicitly drop the backpack. Here's what I suggest:

1. If you have not already, try the keepondeath permission. If that resolves the issue, that suggests there is an issue with the config file.
2. Scan the source code of your plugins to search for API_DropBackpack. Any plugin that refers to that may be explicitly dropping backpacks in certain circumstances, and may have a config option to change that behavior.
3. Test if you can reproduce the issue on a test server with fewer plugins, especially without plugins that use API_DropBackpack.
4. Add a plugin with the CanDropBackpack hook and make it return false. For example, simply add bool CanDropBackpack(ulong backpackOwnerID, Vector3 position) => false; to any plugin. This is just to troubleshoot; I do not suggest it as a long term fix.

I can confirm that i also do not drop the backpack on death without using the keepondeath permission and my setting for dropondeath set to false. (i have 95 plugins running)