Audio Clip Jumps to Random Track When Moving

Greetings All.

In X2aPE, I'm simply trying to drag an audio clip to an adjacent track.
When I attempt that, the clip disappears and is not in the track I drug it into.
Instead, it jumped to a random earlier track.

I'm holding down the shift key to maintain the timing, then I grab the clip with the smart/move tool.

I must have made this move hundreds of times with 8.5, and it worked every time.

When I slide the clip straight up into the previous track, it jumps to a random track, not the one I want it in.


I'm attempting to consolidate audio takes in different tracks into one contiguous track. 
None of the clips overlap.


Any ideas as to why the clips are jumping and not staying in the track that I'm dragging them into?


Thank you,
MG 

CJ,
I've got it set for "Blend Old With New" not "Slide Over and Make Room For".

There's really no blending need, as the clips do not overlap.

Thanks for your time in trying to help though!

Any other ideas?

Cake Support asked me to try it in another project.
Hope to do that in a bit....

Thanks again,
MG