The same thing happened to me after I added some soft coral. Started with live rock which they would swim through and hang around. After adding the coral they did the same thing as your fish. It's been about 2 weeks now and they're making their way towards the bottom again. Give it some time.
My PH level was at a 7.8. I added marine buffer to increase it to 8.4. After adding the buffer my mushrooms started secreting a mucus like substance. Does anyone know why that is and if it's normal?