Zend certified PHP/Magento developer

Centos 8 install blocks admin login

I have been porting my Magento 2.3.7 store over to Centos 8 from Centos 7. Install works okay except for blocking admin logins.

If I update the admin user password using the bin/magento command line tool, then I can log in again. It would appear that the encryption of the passwords is different between Centos 7 and version 8.

What is different between Centos 7 to Centos 8 that breaks the encryption of the admin passwords?