When I set up Scaler 2 in front of a synth that understands aftertouch, it will not pass aftertouch data to the synth.
Are all other midi data passed through (mod wheel etc)? Are you assigning to an instrument that supports aftertouch?
When I tested Scaler 2.0b8 with Bitwig Studio 3.2b5 (as shown in this video) it did not pass aftertouch or mod wheel messages.
When I tested with Logic Pro X 10.5 (as shown in this video) it did pass aftertouch and mod wheel messages.
I also tested with Studio One Professional 184.108.40.206987 (with Scaler on one track and my synth on another) and it did pass pitch bend, modulation, and aftertouch as a VST2 (but not a VST3.)
Could it be a Bitwig problem? (I also tested with Bitwig Studio 3.1.3 and aftertouch/mod wheel/pitch bend messages were not passed. Also, I tested with Scaler 2 on one track and a “Note Receiver” taking the input from Scaler 2 on my synth track and had the same issue.)
which version are you using on the different host VST2 / 3 ?
I just tested using the VST2 version of Scaler 2.0b8 with Bitwig Studio 3.2b5, and it does pass pitch bend/mod wheel/aftertouch. (In the test video I shared, I used the VST3 version.)
I just tested again with Studio One Professional 220.127.116.11987, and had the same issue (VST2 version did pass pitch bend/mod wheel/aftertouch, but the VST3 version didn’t.)
In Logic Pro X 10.5, I used the Audio Unit version and did not have this issue.