[TYPO3-commerce] Problem with special prices - no basket update on login

[Janosch Skrobek / binaryworx]

Hi everyone,

I have a problem with special prices for certain usergroups. Lets say I have
2 prices, one regular one (20 Euro) and one for a special group (15 Euro). 

When I add an article to my basket without being logged in the price is 20
-> correct
I log in, price in the shop changes to 15 but the article in the basket
stays at 20. -> not correct.
Even clicking "update" makes no difference. 

How can I force commerce to always get the correct price?

Regards,
Janosch