In my other phones, I split screen like this...
Hold down the recent apps menu button, immediately a split screen is opened and I can choose my other split screen.
On my S10+, which has Android 10...
I have to hit the recent apps menu button.
Then I have to swipe back to my current app and choose a button at the top of the window and choose split screen.
The, I have to go away and find another app that I want to split screen with.
PROBLEM: this is pants and takes one too many clicks. The old was is MUCH MUCH better.
If I'm watching something on Youtube for example, then my youtube thing I'm watching is paused.
Until a few seconds later, I have to give it another press to play again.
This is causing so much stress. Grrrr!!
What am I missing??
How can I get the old way back??
My previous phone was a Xiaomi. They got clever with the latest release and implemented similar to Android 10.
But, then you had the choice of going back to the old way of spliy screen.
Can I get what I want?
In the "Good Lock" app by Samsung under multistar you can reactivate the feature to long press an app and open it in split or pop up view
(Post about goodlock, check out both posts for some great multi window and pop up view options)
Galaxy store links: Goodlock- http://apps.samsung.com/appquery/appDetail.as?appId=com.samsung.android.goodlock
Theme park- http://apps.samsung.com/appquery/appDetail.as?appId=com.samsung.android.themedesigner
Unsupported regions option- https://forum.xda-developers.com/galaxy-s8/themes/app-nicelock-lock-2019-launcher-pie-t3908650
Hope this helps you solve your issue
You can use the Apps Edge panel, drag an app icon from the edge panel to either top or bottom of the screen. The transparency of the edge panel handle can be set to 100% if it bothers you.