Final Cut Pro 10.6.9 Transitions are not working properly

often when I to drag the transition onto my video nothing happens. I tried the hack for 10.6.2 where you click on you video section then double click on the transition. sometimes this works but not always and specifically my favorite cross disolve isn't working at all. When I insert the cross desolve I can only see a VERY slight split second effect... this example theres absolutely zero effect.not the expected effect that I used extensively in the past. Oddly I drag in the curtin disolve and it works. severely buggy with this latest update