Unable to search in Photos App after iOS 27 update

With a new OS, Photos needs to re-scan all the images, and this could take a while--days if it's a large Library. So, find good wifi, plug the phone in, and leave it alone to let it do its work.

Check in after a day or so, and let us know how this goes…

I have a 16 with iOS 27.0.1, and searches work fine for me. Are you running any VPNs, anti-virus, or "cleaner" apps? Anything with system wide access that includes Photos?

• Do you have “Optimize Storage” checked in Settings>[name]>iCloud>Photos
• Do you see all your iPhone pictures at iCloud.com?
• What is your storage in iCloud? At Settings>[name]>iCloud>Storage, mine says 166.6 GB of 200 GB used. What does yours say? 
• What is your storage on this iPhone? At Settings>General>iPhone Storage, my phone says 50.5 GB of 128 GB used. What does yours say? 

Have you tried a forced re-start of the phone?

Force restart iPhone - Apple Support

This is different from a simple Power Off. For me, the logo appears  5 or 10 seconds past the "slide to power off" message. Wait for the logo; don't do the slide thing. 

Why are you using iCloud? See this:

Understanding iCloud Photos - Apple Community

It's been more than a week now since the last update, although i've been using ios27 since they released the RC.

Still broken for me. This is the longest time i've been waiting for it to finish. It looks like the indexing is either not working, it became much slower or it looped and blocked. I have no idea what's happening.

If it isn’t fixed I will cancel my iCloud account.

Thanks Richard, this is very helpful. My problem may well be down to one or more of the factors you suggest and I’ll run through them. I’m sure I’ll find a solution. All the best.