1st problem. I’m not sure why it happened, but I created a new group channel track for the drums and it fixed it. Maybe it it was happening because the outputs of the individual drum were set to the deleted drum group? Makes sense (I think).
2nd Problem. I checked the outputs and apparently my synth group track was outputing to my guitar group track, causing them to solo together.
Problem solved.
100% pilot error. Still learning the ropes with how Cubase handles groups/links. ect… vs Protools, which is where I’m coming from.