I've tried that, but most of the things are greyed out and anything I try seems to not fix things. I've lately just worked around things by manually cutting and pasting the same piece of the clip. Not nearly as nice as it use to be for me.

Are you importing WAV or REX files? They appear similarly but the rules for handling them are different.

.WAV files

I'd need a recipe to reproduce to help any further, looping works fine here and has for the past 17 years. If it happens to all your audio, it should be reproducible. If it only happens with some audio, then we need to find out what's wonky about the audio.

OK, what I do is take any audio track and drag it into SPLAT. Lets say I need to add additional vamps to the song. I place the cursor at the beginning the vamp. Split the track at that point, and split it again at the end of the vamp. I now have three selectable clips. I move the last clip out of the way, select the vamp and right click and pick "groove pick looping." I'm then given a dialog box that informs me that things outside of that selected clip will be discarded. I click OK. I then see that the clip has either stretched or shrunk. I can then drag it out and get the extra vamps, but they are no longer at the same tempo as the remaining clips. It seems to me that groove clip looping always wants to match the tempo of the template I'm using, not the tempo of the songs I've imported. I've tried importing lots of different audio tracks from different sources and get the same results. Maybe its my template? I'll try a different template to see.

JCody
It seems to me that groove clip looping always wants to match the tempo of the template I'm using, not the tempo of the songs I've imported. 

The Groove Clip will always respect the tempo in the Control Bar Transport.

It didn't use to work that way for me. So I guess that my workflow would have to include detecting the tempo of the audio I import? What if the song has varying tempos? I wish it were simpler. Anyway, thanks Craig for your helping with this. If you find a setting that changes this behavior, that would be awesome.

JCody
It didn't use to work that way for me.

 
It was almost certainly coincidence due to SONAR's tempo matching that of the audio being imported. I've been using SONAR to create loops for 17 years, and the loops always follow SONAR's tempo.
 

So I guess that my workflow would have to include detecting the tempo of the audio I import? What if the song has varying tempos? I wish it were simpler. Anyway, thanks Craig for your helping with this.

 
There are several ways to detect tempo. I wrote an "old school" but reliable way to do this with X3, but the principles are the same. 
 
AudioSnap is another way to determine tempo from a clip, but you'll need audio with fairly defined transients.
 
The most space-age and wonderful way to do this, which also takes into account varying tempos, is the tempo detection feature that was added in the 2016.03 update. Its ability to create a tempo map from existing audio is almost magical.
 

Thanks Craig,
 It must've been a crazy coincidence. I tried the tempo mapping ARA melodyne thing. It'll have to do. It for the most part is an amazing feature. It doesn't work all the time as I'm usually editing musical theater music which can be ridiculously complex and subtle in its tempos.
Ha! now that I remember, I realize that it always worked perfectly when I was working with midi. It all makes sense now.

JCody
Thanks Craig,
 It must've been a crazy coincidence. I tried the tempo mapping ARA melodyne thing. It'll have to do. It for the most part is an amazing feature. It doesn't work all the time as I'm usually editing musical theater music which can be ridiculously complex and subtle in its tempos.
Ha! now that I remember, I realize that it always worked perfectly when I was working with midi. It all makes sense now.

Changing the Melodyne algorithm to Percussion can also make it work better.