Description of the issue

When monitoring network switches via SNMP using Zabbix 8.0, items that collect interface traffic volume do not store any data and remain completely empty (blank) in the "Latest data" screen. No errors or warnings are shown in the frontend.

Static SNMP data (such as "Admin status of interface = UP") works perfectly on the exact same host.

Steps to reproduce

1. Add an SNMP network device to Zabbix 8.0 using a standard interface template.
2. Ensure the item prototype uses `IF-MIB::ifHCInOctets.{#SNMPINDEX}` with Type of information: `Numeric (unsigned)`.
3. The item has the following preprocessing steps:
   - Step 1: Change per second
   - Step 2: Custom multiplier (x8)
4. Wait for multiple configuration cache reloads and discovery intervals to pass.

Expected result

Zabbix should successfully calculate the data delta using "Change per second", apply the multiplier, and display the bandwidth utilization in bits per second.

Actual result

The "Latest data" page remains empty for these specific traffic items, even after forcing "Execute now" multiple times. 

Additional CLI verification

A manual check from the Zabbix server CLI using `snmpget` fetches the 64-bit counter value instantly and correctly:
$ snmpget -v 2c -c public 192.168.155.222 IF-MIB::ifHCInOctets.436207616
IF-MIB::ifHCInOctets.436207616 = Counter64: 177641905

It appears that the preprocessing manager silently discards the Counter64 data or fails the type conversion when combining "Change per second" with a "Custom multiplier" in the new Zabbix 8.0 engine.