Google in the application billing verification failed sometimes

Question

Our server sometimes cannot verify the signature for Google Wallet. Sometimes it works, sometimes the check failed.

We use the following guide - https://developer.android.com/google/play/billing/billing_integrate.html

and after implementing Java - https://github.com/anjlab/android-inapp-billing-v3/blob/master/library/src/main/java/com/anjlab/android/iab/v3/Security.java to Verify the server side signature.

I noticed that there are 2 types of orders, for example - GPA.1391-1084-0175-28517, orders starting with the GPA are checked correctly.

Checking orders, which looks like: 4781656834035199745.4951372150438022 or 4557257650215229301.5495206017032115 or just 8120126244668862748, always fails.

In addition, I cannot see the failed order IDs on the Google Merchant Admin screen. There are many such orders from different users created at different times, it does not look like someone is trying to hack us.

Any key is welcome.