I've repaired multitudes of shoes and sandals using Loctite GO2 All Purpose.
Use liberally without oozing .. or clean excess well before it sets .. or let it bead and trim the excess after curing.
clamp for 24 hours <<-- important
None of the shoes that I have glued have given out in the same place.
I dislike this glue for everything, it doesn't like to hold. With shoes, for some reason, it works extremely well.
I've tried 'shoe goo' .. it does not hold as well.