The setting is min trust level for user api key set that to 0 to allow anyone access to that app.
Regarding logout see:
https://meta.discourse.org/t/report-of-user-unexpectedly-logged-out-iphone-safari/65761/2?u=sam
I wish I could fix it, you can somewhat mitigate, but until Apple properly fixes it there are no 100% reliable workarounds.