Sometimes simple things can be confusing:
I work with two SAP GUI for Windows sessions parallel. On the one hand TAC SE80 with a report and on the other hand TAC BOBF with a BO, especially a query. I add a filter structure, save and activate the BO. Now I switch to the report and want to continue my coding – but the code completion ignores my changes in BO, it doesn’t offer my query. After a while I found out, that is necessary to restart the TAC SE80 – then the code completion works perfect.