I am using Flexform 1.8.41 in WP 4.9.7 and am having issues editing in Swift Page Builder.
When I edit an element and click Save, the page is OK but when I click Update, the page reloads in Text view in Classic Editor every time. So then I have to click on Swift Page Builder, then Visual mode before continuing with edits.
If I add an H1 Title in a Text Block or Message box etc. then click Save and Update, then go back to Swift Page Builder editing mode and open up the element again, I find an extra paragraph inserted before the H1 element and when I view in Text mode, I see there is an “empty space” character that has been inserted: " "
Regardless of how many times I delete the extra paragraph with the then Save, Update, revert back to Swift Page Builder, and reopen the element, I see the additional space and character.
I’ve tested this on Chrome and FireFox on PC and Mac and it is the same on all platforms.