It's not just a waves problem. It affects all VST3 plugins.
I reported a similar bug in X3, but it hasnt been fixed in SPLAT:
1. drag a vst3 fx to a channel fx bin
2. In the inspector click display > module options > fx > show assignable controls
3. Move the bypass control (or any control)
RESULT: All the controls are shifted by 1 and get assigned to the wrong plugin parameter
The reason I think this happens is because the VST 3 HOST BYPASS parameter gets added as the first parameter in the list