I had SpectraLayers 7 with my Cubase 11 update and just updated to SpectraLayers 8 but realized that it must be the demo version because there is no “unmix components” option available. Is it not free with C11?
Check that you have activated the SL8 license you got when you updated. You should see it in the eLicenser Control Center (eLCC). N.B. the “unmix components” is an SL Pro-only feature. Do you have an activated license for SL Pro 8?