groove clicking when buffer contents selecting/scrubbing

Here is an excerpt from a patch I have created. I use two midi controller knobs to select areas of buffer content (by moving the 'selection start' and 'selection end' inputs of a waveform object) played by a simple groove. I have (in rudimentary fashion) patched some logic that gets rid of the click when groove finishes and restarts its loop. However I cannot work out how to erase clicks when moving both the midi knobs at the same time, ie sort of scrolling through the buffer (at speed - when you 'scrub' slowly the clicks arnt around). Problem is I havent really pinpointed the exact root of the clicks...

I always play the groove at a sig value of 1.

The musical content that i record into my buffer is played on the cello.

Any help would be greatly appreciated!

Thanks

Here is the summarised patch excerpt: