In order to determine whether to show or not the OPEN button, the app needs to scan and verify that the locks in your surroundings are KleverKey enabled.
Android 7 and above
There is a non-documented BLE behaviour that affects the performance of our KleverKey app for Android versions 7 and above. It was mentioned in the DP4 release notes of Android 7:
We’ve changed the BLE Scanning behavior starting in DP4. We’ll prevent applications from starting and stopping scans more than 5 times in 30 seconds. For long running scans, we’ll convert them into opportunistic scans.
Navigating repeatedly between the keychain and other screens in a short time lapse.
In the case where you are in front of the lock and it doesn't appear the OPEN button as it should, pull-to-refresh the Keychain.
Why does this happen?
A very clear blog post explains the technicals behind this issue.