I mean, everyone is different, but I put on a prodigious amount of muscle on keto. As long as I'm eating enough protein and training hard enough.

Nowdays not doing keto anymore for practical reasons and still packing on muscle. For me carbs has very little to do with that.

Energy source (mostly fat if keto, fat+carbs mix if not) + 200g protein/d + rest + progressive overhead w/o overtraining = buff.

Are you tracking your macros? Getting enough sleep? Lifting a bit more weight every week and/or adding some reps?