It is something that I have noticed that might need to be improved upon. Depending on your routing settings (document vs. site), the / might need to be added or not added.
I normally like relative to site over relative to document but i recall there were issues with routing in the early days if things were set relative to site so I tend to leave settings at the default, relative to document
Then it’s the same. Unfortunately i cannot recreate this.
What is the structure you are using i.e. where is the page you are redirecting from located?
Is this a SPA or just plain URL rewrite?