Use matching reference levels on sending and receiving analog port.
UFX II: choose a higher reference level on the UFX II's input to get more headroom and check that you do not use digital gain on top. You find those settings in TM FX, click to tool/wrench symbol on this particular HW input in the top row of TM FX.
Sending device: choose a suitable reference level if possible, either consumer or studio level that matches the UFX II settings.
If the device has a knob for controlling the output level, you can also turn it down a bit.
BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub14