I have been working for quite some time on a website that highly depends on Paypal working properly on it. Without it, it is really useless.
Around 1 in the morning
Try add
CURLOPT_SSL_CIPHER_LIST => 'TLSv1'
to your PPHttpConfig.php file. I had the same issue with you and spent hours to find the solution. This worked for me.
PPHttpConfig.php