email/user id case-sensitiveness at the verification step
My unit uses belenios (loria instance, 1.17) for our CCPL election. It works flawlessly for me, save the last step "verification by email". This step mixes two things together: user id and email. The user id seems case sensitive, but an email is traditionally case insensitive. I always capitalize my first and last name in my email. Indeed, capitalizing my email differently from the user id leads to failure at the verification step (hopefully with a small loop to redo it).
I would canonicalize both entries (user id, email) to lower case before checking their equality.