A lot of satisfaction surveys which were supposed to be sent in the last week were sent today, due to a bug in our code. The issue has now been fixed and satisfaction surveys should be sent in the expected timing from now on.
In addition to this delay, due to a performance issue (consequence of the high volume of surveys being sent at the same time), some of those surveys have been sent multiple times to customers (around 4 to 5 times). Similarly, this should not happen again moving forward. We're also going to add more security checks so that a satisfaction survey can never ever be sent multiple times.