Why do i receive "Project Number is not in the list of values" error for split allocation?

Summary:

Even though the project being used for an expense is valid - when using the split allocation feature, i receive the error shown in the page illustration below. This makes using audit not workable, as well.

Content (please ensure you mask any confidential information):

Version (include the version you are using, if applicable):

Oracle Fusion Cloud Applications
26A (11.13.26.01.0)
Oracle Redwood 2601.2.0

Oracle Application Development Framework
JDEVADF_14.1.2.24.0ADF-REL132601-PROD-BP_GENERIC_260211.1949.S

Oracle Middleware Extensions for Applications
ATGPF_PT.14C.2601_GENERIC_260110.1333.REL13BP101.3
Database Compatibility TRUE (REL13BP101.3)

Code Snippet (add any code snippets that support your topic, if applicable):