Thank you Luis, I appreciate your fast response.
For example, I open both Safari and Photos. Click on the green button in Safari and tile it to right or left. And then try to click on Photos, but get a circle with a slash, saying not available in Split View. (Same thing happens with Messages, Power Point, etc)
When I try, I get a pop up message saying the windows are not compatible. Or that there are no available windows.The settings are all properly configured.
I've been using this on previous OS and it worked beautifully. I did find that if using Chrome, and not Safari, I can split the screen with Photos or other programs with no problem.
I can't drag & drop a photo into Messages, or email, or from Safari into PPT
I can't have 2 applications open on the screen. It's very frustrating.
Clearly the answer is to switch to Chrome, but I prefer Safari for a variety of reasons.
Thank you for any help you can offer.