Thanks guys, I called them and the flights were updated. I don't see my seating assignments on Manage my Booking (even for the unchanged leg) but I hope everything will be fine when it comes to OLCI...
I now have a similar problem with my mom's booking where flight times were also changed. In her case the option to confirm does show up in Manage my Booking but the following error message shows up when trying to do so:
Dear passenger
We are sorry, we cannot process your ticket issue transaction. Refund of your payment will be automatically processed. In case of failure to refund automatically within 3 days, you may issue a refund claim through our feedback form.
Called customer service and they also said that some sort of error message shows up for them and they cannot confirm, and that I should try calling them the next day...