Hi Liam. I love Stimy's! They are actually rather expensive here is the states. I have been wanting some of these, and some ants.
My first question is, what are the actual temps in the viv? And how is it set up? You said two CHE's, are they on one side with the other being cooler? Overheating can cause stress that could be displayed in such a way. One of the most important things with any reptile is to know the actual temperature, and this goes even more if you change the type of heating device.
And, you said you are feeding two fuzzies at a time? How big is she? She looks to be close to full grown. You might be better with 1 small hopper. And second part, re you feeding live, pre-killed, or frozen/thawed?