Hi Max, welcome to the forum!
1) so to get sound out of the Acid Groovebox you need to keep tapping the pushbutton, or better: feed a clock into the PUSH input (left one). Still low? How about the XFM Oscillator patch, also low?
2) that doesn't seem right. It's worth checking the device input/output gain settings with OwlControl. On the OWL Modular they should be 0dB in and out by default ('low' sensitivity setting). That should be perfect for Eurorack modular levels.