Indirect Tag reference property issue

Bit of a weird issue wondering if I am doing something wrong. But while using Indirect Tag binding. After I put in the tag path and reference the ID when I input the property for it after I press ok and go back to it the property goes blank. Is this an issue or am I doing something wrong? Screenshot to show what I have done

There's a quirk in that editor where, after you close the dialog for the reference expression, you have to hit enter one more time to make it "stick".

Yeah, annoying.