Signal from Mixer Send into uTrack24 Too Hot for Recording but Normal for Mixer

Hi,

I do not say that. I said the inputs designed to handle balanced connections max +20dBu input levels.
You can still use the device to connect unbalanced signal but this needs a modified cable.
To have a proper connection please take a look at the pinout of the DB25 connector:

To make the connection to unbalanced you can use that kind of connection (on the drawing you’ll see the XLR connector, you need to use that pinout on the DB25 connector)

or