DNS does not update the dns zone serial after making changes

Sorry I'm using a translator.

I am using CWP Pro version 0.9.8.932 on 3 different servers, and in all of them the same symptom occurs. When editing the DNS zones, in the administrator panel or in the user panel, in the serial of the dns zone it updates the first 8 digits, but does not update the last 2.
For example this change made on 20/01/29, if you change the records it does not update the last 2 digits, which should add +1 to the end.
2020012900; serial, todays date + todays

Someone with the same problem or solution for that?

CWP released an update and it worked correctly.

I am using version 0.9.8.985, and the problem of not updating the DNS serial again occurred. Someone with the same situation? or tips on what to do to solve?

I am using version 0.9.8.990, and the problem of not updating the DNS serial again

We have another 4 servers running with version 0.9.8.990, we have the DNS Slave also running on the CWP and the serial update is not working.

Updated the CWP to version 0.9.8.991 and the problem of not updating the serial of DNS zones persists.
Does anyone know how we can solve this?

Updated the CWP to version 0.9.8.994, and even then the DNS zone serial still does not update. Any procedure on how to solve?