I had the Bitdefender options greyed out on my Macbook macos for Quick Scan, System Scan, and Custom Scan. So I went to the upper left main menu, Actions -> Custom Scan ...then it popped up the previous 'results' type page from my prior single file Custom Scan...it was still waiting for me to hit the "Close" button from that prior scan. Once I closed that previous result, then I could do a new Custom Scan and the other 2 were no longer greyed out. I just tried to recreate the issue, but it seems to be behaving better, defaulting to functioning, if I just X out of the results page, or if I just close the app...not sure how it got stuck in that state with Quick Scan, System Scan, and Custom Scan greyed out...