Cannot publish app either testing nor beta

[metalbote]

Hello,

I just ran into the following problem. When creating a new app I am not able to publish it after checking the release. I'm getting a warning that the target SDK must be version 26 from August, and that the version I compiled in the cloud is only version 22.
Although it is only a warning, I cannot publish the internal test.

Is there a flag so I can compile the app with target SDK 26? Or another workaround.