Second Acess 2 Developermode does not work

hey guys, something stranger...

first time all works great and i can switch to developer mode. but i want to copy some files from pc to the quest. so i disabled the developer mode in the smartphone app. if than i connect quest via usb 2.0 or 3.0 to pc it asks to allow file access. ok, so files can be copied to the quest. now if i connect the quest to pc i only get this question and developer mode is in the quest off, can't see the bullet point in navigation tab in quest. if i want to activate developer mode by the smartphone app (is there any other way?) i only got the message "failed, can't access to developer mode, try again" <- sorry i have the german version but this is similar to the german message.

so what can i do to get access again to developer mode?