Do you have a multimeter? Or other way of gauging the resistance of the new traces?

I don’t know the specific product you’ve used, and my experience with conductive paints and glues is almost nonexistent. But what I remember is that it was neither useful as a glue or a conductor. So I suspect that the resistance of the trace is too great to be used for traces going into the 100s of mm.

If my suspicion is correct, then maybe you can fix it by using the paint to attach something with little resistance in parallel to the paint traces. Maybe stripping a multicore wire and using a single strand of copper, lay it down on the trace and paint over it? Or cutting the traces out of tinfoil and gluing them down to the existing traces with some of the paint?