.htaccess – multiple htaccess redirects to a new domain

I’m trying to redirect an entire domain over to another domain while also redirecting a couple of specific pages to specific locations. I also want to preserve www and https on the original domain to ensure there are no errors on the old domain and any links will still work/redirect correctly.

Here’s what I’ve got so far — the https, www, and sitewide redirect work fine, but the page to page redirect(s) don’t do anything:

RewriteEngine on

# Force HTTPS and WWW 
RewriteCond %{HTTP_HOST} !^www.(.*)$ (OR,NC)
RewriteCond %{https} off  
RewriteRule ^(.*)$ https://www.OLDSITE.com/$1 (R=301)

RewriteRule ^/?OLDPOST1/?(.*)$ https://NEWSITE.com/NEWPOST1/ (L,QSA,R=302)
RewriteRule ^/?OLDPOST2/?(.*)$ https://NEWSITE.com/NEWPOST2/ (L,QSA,R=302)
RewriteRule ^/?OLDPOST3/?(.*)$ https://NEWSITE.com/NEWPOST3/ (L,QSA,R=302)

RewriteRule ^(.*) https://NEWSITE.com (L,QSA,R=302)

Any idea what I’m doing wrong? Thanks in advance!