For example *crypt* only returns hits on "crypt" and not "decrypt".
Examples:
1: https://stackoverflow.com/search?q=*crypt*
2: https://stackoverflow.com/search?tab=newest&q=*crypt*
3: https://stackoverflow.com/search?tab=newest&q=decrypt
Note that the results of URL 3 should appear in the results of URL 2.
This has happened in the past with updates, regression testing might be a good idea. Also global changes are best not done on a Friday afternoon.
Update:
#Update: ItIt appears that SO search meta-characters are working correctly when SO is accessed from EU/Deutschland but incorrectly when accessed from the US.