After update to version 3 the config ignore do not ignore the first element

It seems like you have found out what the issue is.
The sorting (ie what this issue title suggests) is higly unlikely to be the problem. We have tests for it but more importantly the order you save gets sorted both for export and when it is actually used. So if it works with one order but not the other then something extra strange is going on and would point to some other module interfering.

You found out that config ignore and config split both change what config is imported and exported. In fact they both work in very similar ways. It is generally not a good idea to both ignore and split the same config. But if you must, then you can adjust the priorities in which each split and also config ignore run to suit your needs.

After some testing seems like more of a problem of config_split than config_ignore.
Thank you.

Hi, no I think the problem is the interaction between the two. If you split some config then it will "win" depending on the order.