We are experiencing issues with the search facility as well.
Not sure which dates are actually affected, but certainly searching on this month's incident numbers and/or key words written is very much hit or miss. This issue has been experienced by the vast majority of my service desk team. In the instances, where we know the incident number, then keying it in the web address, does the trick. But, we don't always know this.
This seemed to break again recently, but is working today. We are unable to search/link incidents created between 8:00am CST on 8/16/2017 and 3:20pm CST on 8/24. Anyone else have similar issue between that time frame? We can search using the B#, but unable to link those incidents. FRUSTRATING!!