Built in guitars bug?

This is seriously difficult to explain as it seems to be a constantly changing bug. Essentially what is happening is that most of the built in guitars and bass sounds are only coming out of the left side; not all of them but most of them. This is through my audio interface Behringer U-Phoria UMC22. I also have a brand new Focusrite Scarlett Solo interface which, when I switch over to that, a few more of the guitars work fine but most of them are still only coming through one side - this time it's the right side. A few minutes ago I recorded a piece using the guitar sound 'UK Vibration', in 'Crunch guitar' and it was working fine on both sides. I then changed the sound of that channel to 'Big Spinner' (also in the Crunch effects) and it works loudly on the left side only. However, I then duplicated that track to record again with the same sound, and now it's really quiet, still only on the left side (wtf???). I've tried everything to resolve this, even to the point of uninstalling Logic and reinstalling it. I have two different audio interfaces, one of them brand new, so I can't figure out why this 'bug' is acting differently with both of them. This has only started happening recently and I've never experienced it before, having used Logic Pro X for the past 5 years at home and at college. It just seems to me that Logic has a mind of its own, and does whatever it feels like, and I have no idea how to fix this as there's nothing online about it whatsoever. Please help!

Are you recording through one input on your audio interface into a stereo track perhaps? This would only give you the one sided result, and depending on the effect you apply it could sound different if it's spreading it across the stereo field or not, some of the built in guitar patches also feature twin amps hard panned also which would exacerbate the effect.

 

Input 1+2 is a stereo in, but using only input 1 OR 2 should be set for mono, or you will get a hard panned result (Depending on your audio interface setup if it has any management/routing utilities).

 

With guitar direct in, You should be recording one input to a mono track setup, i.e. this:-

Stereo[/attachment]

 

Simply click the overlapping circles to change to mono and select either Input 1 or 2 - whatever corresponds to your guitar input on the interface, then try recording guitar.

 

This is what I have found after following your instructions.

I've also now realised when I play some of the guitar sounds they are actually giving me lots of feedback/loud noise in the left ear but the normal guitar tone in the right ear, this must be a new thing as I've been through all the guitars to see which ones I can use and which ones I can't and I haven't heard this before.

Yep, you've chosen a stereo track which is expecting two signals from your interface. Make it mono and select a single input. (You can still have the plug-in as stereo output if you want reverb, delay plug-ins etc in stereo.)

As the other posts, click this bad boy (Circled red) to mono/stereo toggle and you'll be good.