You find there is always a company code assigned for a G/L account in app Display Line Items in General Ledger.
SAP S/4HANA Cloud
Reproducing the Issue
In app Display Line Items in General Ledger, input a G/L account, and then click ENTER, the company code is automatically filled.
It is the system behavior, after you fill the G/L account, the dropdown list indicates all the company codes assigned to it, if you click enter, system will select the first entry in the dropdown list.
The workaround is to press the SPACE key once after filling the G/L account, in this way there will be no company code assigned any more.
Display Line Items in general ledger, company code, G/L account, automatically, default. , KBA , FI-FIO-GL-IS , Reporting Apps , How To