Bo

One question before you accept that the update caused it: did anything else happen in the same week? A restore, a transfer to a new device, a storage cleanup, or an app offload.

I ask because offloaded apps behave exactly like what you are describing. The icon stays, search still finds the app, tapping it downloads it again — and until it has been launched properly it has nothing registered. If you have Offload Unused Apps switched on and the update pushed you near the storage line, a batch of apps can get offloaded at once, and the result looks like the update ate your shortcuts.

Settings, General, iPhone Storage will show offloaded apps with a small cloud on the icon. Cheap to check and it would explain why launching each one fixes it.

Adding the one thing that is missing from every version of this list: check that the thing you are searching for is allowed to be found at all.

Settings, Siri & Search has a global section above the per-app list, and there are switches there for what may appear in search and in suggestions. There is also Screen Time content restrictions, which can quietly exclude things and which people forget is on because they set it up for a child two years ago.

It is not a rebuild, but I have watched two people chase an index problem that was a restriction. Rule it out before you spend a night on it.