If SNMP walk is used for the master item for LLD and then SNMP walk value preprocessing step is used for the dependent item, then a space is added to the end of the returned string:

Master item:

walk[1.3.6.1.4.1.6527.3.1.2.2.1.8.1.5,1.3.6.1.4.1.6527.3.1.2.2.1.8.1.7,1.3.6.1.4.1.6527.3.1.2.2.1.8.1.8,1.3.6.1.4.1.6527.3.1.2.2.1.8.1.16,1.3.6.1.4.1.6527.3.1.2.2.1.8.1.17,1.3.6.1.4.1.6527.3.1.2.2.1.8.1.18,1.3.6.1.4.1.6527.3.1.2.2.1.8.1.19]

Dependent item :

SNMP walk value : 1.3.6.1.4.1.6527.3.1.2.2.1.8.1.5.1.50790401

2025-04-22 09:38:11 1745307491 "CZ22080DVN "

If we use SNMP get directly on the OID data in the item, there are no space in the received value::

get[1.3.6.1.4.1.6527.3.1.2.2.1.8.1.5.1.50790401]

2025-04-22 13:55:10 1745322910 "CZ22080DVN"

Additionally:

As can be seen from the command outputs, there is probably a newline character at the end of the strings and Zabbix will either truncate this character (get[OID]) or replace it with a space (walk[OID] or OID). 3 versions of the item configuration and their output in Zabbix: