I installed Feeder from F-Droid. On August 9th a major 2.5 update was released that I would like to have but it is not yet updated in F-Droid.
I downloaded from GitHub - spacecowboy/Feeder: Android RSS reader app the app.release.apk file with version 2.6 and it could not update on the phone.
The f-droid version and GitHub versions have different signatures. If you don’t want to wait for the newer version to reach f-droid, you will need to export your subscriptions, uninstall the app and install the app you downloaded from GitHub and restore subscriptions
Thank you for your prompt response. The problem is that the latest update includes export the list of filters, so I will have to wait for F-Droid if I don’t want to lose it.