If I understand from your reply, this problem has nothing to do with Scrivener and only with ProWritingAid.
As a customer, this is annoying. I spent $120 on PWA mainly because it claimed to work “seamlessly” with Scrivener. However, there’s minor but frustrating issues with things such as indenting, smart quotes, and apostrophes not recognized properly across the two softwares. And their customer support is non-existent.
If Scrivener is in no way involved with PWA, I would advise Scrivener to look at the claims they make regarding their compatibility with Scrivener. You don’t want other companies selling a product priced three or four times than Scrivener with explicit, false claims of compatibility and seamlessness.
I did some tests.
It’s a ProWirttingAid bug and a pretty serious one.
When pressing Enter it displays it like a NEW PARAGRAPH with larger line spacing, but saves it as a NEW LINE.
When you press Shift-Enter and it shows line a NEW LINE with a narrower line spacing, then saves it as a NEW LINE also.
When I turn on Invisibles in Scrivner and look at the saved all then line breaks as NEW LINES.
And If I save and close the file in ProWritingAid and then reopen, without ever opening in Scivner all the line spaces is the same. So it clearly saved all the line breaks the same way.
So as it relates to New Line and New Paragraph. ProWrittingAid is broken. That is why the start of paragraph indents don’t show.
Well, as others have suggested, much the best to report to ProWritingAid Support that you and others are trying the BETA of Scrivener 3, and finding issues.
I had a look and there appear to be more than you’ve noticed yet.
For the time being, you can still use PWA effectively with the Scrivener beta. Just copy-paste text blocks between the two.
Your downside will be that inline formatting like italics or bold will get lost, though with thoughtful pasting (not over the top) you can reference the original and correct that.
Once PWA gets used to the upgraded file arrangements in Scrivener, then you’ll get the full integration, including the handy binder-selection back. And so will all the rest of us who use PWA for its merits.
I’ve communicated with them about this issue for months now, and as far as I can tell, they have finally resolved the issue where PWA inserts a soft line break instead of an end of paragraph marker when you hit Enter.
In short, as of version 2.0.36 (released 16th of March) I’m no longer seeing the problem.