There usually is some delay before added or changed tags will show up in searches. It may be that some special process, like periodic backing-up data, has to be done before the recently added tags will work, so I wouldn't be surprised if they don't all show up in a search on the day that they're posted.
I frequently use the Search facility in different ways, so am used to that delay for recent entries, but haven't encountered any problem with them not working on later days. Do bear in mind that Blippers in other parts of the world may well be uploading them on what is the following day in your part of the world! Or that some of us don't always upload entries on the day they were taken... guilty here.
PeninsulaLight (& Film)