Android sqlite DB changes not saved after reopening app

I'm trying to save changes I make with a pool executor when each of 3 events occur in my app (data goes from fragment A to B, vice versa, and when I click RESET button). These changes should load when I reopen the app.

The problem is,even though while the app is running, I can see the changes in the DB are made as they should be ,but when I reopen the app the DB is in the same state as it is when the app is first installed.

Since I can see that saving data to a db is made properly, I can't really think of or pinpoint a possible class or brief of code that causes the issue.

Any advice would be much appreciated . Thank you.