If using an Android platform, you have to turn off "Auto-Updates" in your Google Play settings, otherwise Google will update Kodi, even if you Sideloaded the app from another source.It was a pain in the ass, I deleted 19.1 and went back 18.9.
Thanks
How to disable auto-update apps in Google Play
1. Open the Google Play Store app and tap on the 3-bar menu icon on the top left. Then scroll down and choose Settings.
2. In the Play Store settings, tap Auto-update apps.
3. You'll see three options (which can be changed at any time): Do not auto-update apps, Auto-update apps over any network (using your data) and Auto-update apps over Wi-Fi only.
4. Choose Don't auto-update apps. / Click Done.
*Note that this means you will always need to manually update all apps in the future.
/Shooty