Billing graphs not correct?

Hi

Our billing graphs are reporting about 10% more traffic then our provider is reporting to us. In the past we had our own tool which was getting the counters from the switch port and this was the same as our provider was reporting so it seems there is a difference in LibreNMS. Are there some configuration options to make concerning the billing module what can explain the difference?
Anybody else encountering this issue also?

librenms@librenms:~$ ./validate.php

Component Version
LibreNMS 1.57
DB Schema 2019_10_03_211702_serialize_config (145)
PHP 7.2.17-0ubuntu0.18.04.1
MySQL 10.1.38-MariaDB-0ubuntu0.18.04.1
RRDTool 1.7.0
SNMP NET-SNMP 5.7.3

====================================

[OK] Composer Version: 1.9.1
[OK] Dependencies up-to-date.
[OK] Database connection successful
[OK] Database schema correct

How about the normal SNMP graph for that port on LibreNMS (not billing module), how does that compare ?

same result. For example for one week:
LibreNMS:
in -> 4,54TB
out -> 14,8TB

Provider:
in -> 3,72TB
out -> 13,45TB

Any idea?

Anyone having this issue also?