Points for completing exercises are not being awarded.
I have this problem too. Have just completed 2 exercises in a row with no mistakes and DL awarded no upgrade! This is pretty disheartening. Surely the idea is to find language learning fun and encouraging, not annoying and frustrating?
I have just worked through seven exercises and was accredited only ten points. If this happens again I will quit indefinitely.
Duolingo - this still happens. Please can you work out a system where if you have done well you earn some reward. Isn't that basic psychology?