hey , there, thank u so much for the detailed feedback, on it stopping to work after a while , that's not expected as its a free feature, we'll look into it, yeah grouping subs wrong is an issue, just wait a few days for the update, we're quickly fixing that,speaking of missing a few words in the subs , that's just youtube auto-generated closed captions that we use , so we cannot actually help out with that. We are actively working on all issues thanks for your patience!