I have Elements 8, Steinberg CI1 and the t.bone SC-300 mic.
When I speak into the mic I can clearly hear myself, and when using it on Skype others can hear what happens in the other end of my room. But when I record from my western guitar, the sound is really low. I have to put the guitar in almost point blank of the mic and still, Cubase only records when I hit the strings. But short after I’ve hit the strings the sound isn’t recording, even though the guitar is clearly still generating lots of sound (hope this explanation makes sense).
The noise gate being suggested would be a plugin in an insert on the channel you are recording to or on the input channel inserts.
If you are using a template there may have been a gate already inserted or if you are using a guitar amp vst for example it may have a built in gate.
A gate (aka noise gate) is a fancy automatic on/off switch. It turns on when the signal coming in is louder than a certain level that you can set. And it turns off when it’s below that level. For example a guitar amp often generates a bunch of noise even when not being played, which generally you don’t want to record. A gate will only let the signal through when the guitar is actually being played, thus keeping out the unwanted noise. But if it is not setup correctly it could also cut out some of what the guitar is playing. Here’s a detailed description Noise gate - Wikipedia
Like Grim said it would be on an insert. Just turn it off like any insert. Or open it and learn how to set it properly.
A gate is your most likely culprit (but you should still play with mic placement to get the best sound).
