YouTube app completely unopenable

Opening the app instantly closes it, it doesn’t even load the home page. What I have tried:

- Reinstalling the app. Makes it work for a few hours.
- Restarting the iPhone, no change.
- Installing an IPhone update, no change.
- Clearing 20 free gigabytes of space. No change.
- Googling it, no further advice.

What should I try next?

iPhone 16 Pro, iOS 26.5.2, 101.26gb/128gb