Catalina and eGPU issues

I have a 2015 21.5 4K iMac with a Radeon 7870 GHz Edition in a Akitio Node. It has been working perfectly with High Sierra and Mojave. I updated to Catalina and have had performance issues such as less FPS, more rendering time, and temperatures seem to be a little higher than normal (compared to the other iOS's). It hasn't overheated or anything, but while I was rendering and looking something up online I noticed my iMac flickered white, but not on my other monitor just on the iMac. I guess what I am asking is has anyone noticed problems like these with their computers? If so what did you do to fix it?

Extra Info:

Processor: 3.1 GHz Quad-Core i5

Ram: 8 Gb

Built in GPU: Iris Pro Graphics 6200

eGPU: AMD Radeon DD HD 7870 XT GHz Edition