It's hard to tell exactly what's causing the problem without actually seeing the carpet. But what you're describing sounds like the carpet is loaded with soil down at the backing.
If you will pry apart the tufts of fiber and look down at the backing, I believe you'll see that the backing is no longer white. Latex is white so the backing should be white. But sometimes when a CGD carpet gets high traffic, combined with inadequate vacuuming, and/or inadequate cleaning, the backing loads up with soil.
A CGD carpet with a soil plugged backing can cause weird striping when it is wet cleaned using any level of moisture, regardless of whether it's encap or HWE. The fact that you saw this with your RX-20 and with encap adds to that. And it explains why bonnet/pad cleaning (which uses less moisture) didn't affect the soil in the backing.
Soil can load up in the backing of a CGD carpet since the tufts of fiber are so densely packed together. And no amount of pre-vacuuming, pile lifting, or HWE flushing can get it all out. Once the crud pushes down to the backing and gets compressed under the dense CGD pile, it can be next to impossible to remove. That's why it's so important for the building to have adequate walk off mats, a good vacuuming program, and a schedule of regular cleaning intervals.
I have personally run across a handful of CGD carpets that gave me trouble using any level of moisture at all (even encap). In these cases we will normally clean with as little moisture as possible, and then we'll post-pad/bonnet clean them, and they turn out perfect. Sounds like this is what you're up against on this particular account.
If I can help you out, shoot me an e-mail...
rick@excellent-supply.com
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