Why has root domain lower PA than Exact url?

I notice that my domain has a lower PA in SEMRUSH if I set it to Root Domain than if I set it to Exact URL ?

Root is only 41 in PA while Exact url is 66

Is there anything I can do to get the entire juice to the root domain? or what could course this issue if it is a issue?

It's been like 15 years since Google started considering subdomains as separate domains.

If a subdomain has a billion links to it, and the root domain has zero, the sub one will have higher metrics.

Also if you're promoting the subdomain (www or whatever) then you should 301 the root domain to it.

thank you very much...sorry if that is an noob question

I promote https://www.XXXXXXXX.com

I entered xxxxxx.com (root domain) in semrush and it shows 2700 Organic Search Traffic and Ath Scor 41
Now I switch to:
xxxxx.com (EXACT URL) and SEMRUSH shows Page Auth. 66 - No DATA found for Search Traffic

I noticed that SEMRUSH say Authority score for domain root and Page Authority Score for the exact url.

PS I don't have any subdomains.

Maybe it is total crystal clear for most of you, I just don't get it....

no one know this?