An information with type "I" or warning message with type "W" is coded in the Cloud BAdI "Service Document Check Before Save". However, the information or the warning message is not raised in the message log when saving the service document.
SAP S/4HANA Cloud
The "Check Before Save" Cloud BAdI is used to abort document saving. Messages that do not belong to an error with type "E" (such as "I" and "W") will not be raised in the message log when saving the service document.
According to the "Cause" part, this is the standard design of the "Check Before Save" Cloud BAdI. Please consider to raise a new feature request to require for a BAdI with the function of "Service Header/Item Check", within which all types of messages can be raised in the message log.
Please refer to the below KBA for more details about new feature requests: 2963059 - How to Submit Feature Requests for SAP S/4HANA Cloud Product
Information, I, Warning message, W, BAdI, SrvOrdCheckBeforeSave, Service document, Service order, Service confirmation, Abort , KBA , CRM-S4-SRV-SVO , S4CRM: Service Order , Problem