We cleaned a linen sofa with the TMF cotton and linen shampoo and got a call back of it browning. What's odd is we've cleaned this sofa before using a previous product we used prior to switching to TMF and had no issues with it. Since switching to the TMF cotton and linen shampoo we haven't had issues with any other linen either so not sure what the cause is. Any idea what could have occurred and how we can correct? Thanks for your help.