I am having the same issue. I can't test my app.

Has anyone found a solution to this? Now I am finding that sometimes when my app reads a value from userdefaults it does not get the most recently saved value, but a previously saved value. Or sometimes I will get no value when I first attempt to read it, then the correct value if I try again several hours later. Do I need to look for a different way to persistently store values?

I am having the same problem. UserDefaults values that were persistent under iOS 16 are not persistent under iOS 17.