Pam Moore writes
I have checked my Isotoma again. It fits your description; 5 pointed
lavender-blue flowers with white backs, leaves as you say, but I've
checked again, No scent.

Pam in Bristol

You're right! Isotoma (Laurentia) axillaris, I think fantasy blue - and
that does have a scent, though it sounds as if mine is more strongly
scented than they give it credit for, and not just after showers....

--
Klara, Gatwick basin