Changing route numbers

[ModerNertum]

When a new route is created it ads the next number, regardless if you have deleted the previous route. Writing down the new number in the route editing settings doesn’t seem to fix the issue. Is there something else that I am missing here. It’s really confusing, OCD wise.
Thanks for the help 🙏

In short: How do I keep updating the actual route numbers after a route is deleted as the newly added route always remains route 1, if the previous route was deleted?
It only updates in the maplanner, not the save game itself (old route numbers are still shown in the set trip screen, for example).