Downgrade client

After the client was radically updated, I constantly have problems with updating data on my phones. I accidentally find out that the phone has not transmitted data for more than 5 days, for example. On one of the phones, there was an old client that was not updated. Everything works stably and without problems there. How do I return to the old version of the Android application?

Just download the old APK file from GitHub.

Thanks for the advice, but Google identifies it as a malicious application and automatically updates it to a new version.

Not sure what we can do about that.