As @dolik-rce mentioned it's not a Geany issue, but I still have a couple remarks: * not showing some code, it's hard to understand the details of what incorrect code is triggering the issue. * given that you have a fairly old version of Geany, you might also have a fairly old version of shellcheck; thus this potentially has already been improved -- or not, I don't know.
At any rate, realize that understanding invalid code to give meaningful errors is very hard, so we need to indulge shellcheck 🙂