Same here, i wrote to Home-connect support. You can probably do the same i think is a data validation on their end which seems “odd”. Adding an URI/URL without “/” is not possible.
I’m having the very same issue.
Tried different browsers on different operating systems and different redirect URI’s.
No success at all. Have contacted support, so far no answer…
I’ve reached out to Support as well and haven’t received a response. Was excited to get this set up with new Bosch Dishwasher but obviously not right now.