The plesk versions of php are not as they are said to be. For example, plesks php 7.4 is really 7.2
> /opt/plesk/php/7.4/bin/php -v
PHP 7.2.24 (cli) (built: Oct 22 2019 08:28:36) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.2.0, Copyright (c) 1998-2018 Zend Technologies
with the ionCube PHP Loader + ionCube24 v10.4.5, Copyright (c) 2002-2020, by ionCube Ltd.
> /opt/plesk/php/7.4/bin/php -v
PHP 7.2.24 (cli) (built: Oct 22 2019 08:28:36) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.2.0, Copyright (c) 1998-2018 Zend Technologies
with the ionCube PHP Loader + ionCube24 v10.4.5, Copyright (c) 2002-2020, by ionCube Ltd.