There is no setting for the input/output gains to return to 0dB when bypassed. When you bypass an algorithm, the input/output gain settings are not affected.
However, you can save the input/output gain settings in your algorithm presets. In the menu bar, if you select Preset > Save, then this algorithm preset will include your gain settings. You can also save an FX Chain preset that will include each algorithm’s gain settings within the FX Chain.
Let me know if that clears things up for you.