Can't update PHP

We have a customer's website running under php5.6. We want to update to php7.3. Current specs: Centos 6.10 WHM 84.0.9 EA4 Apache 2.4.41 PHP5.6 PHP-FPM Using WHM, selecting PHP7.3 results in this confusing word salad of an error message: Error: (XID xrdcdc) 1 error occurred: Error #1: The system failed to apply the "PHP" version to "user.domain.tld": Cpanel::Exception::IO::ChmodError/(XID drz5xk) The system failed to set the permissions on one or more inodes to "0644" (as EUID: 523, EGID: 536 536) because of the following error: Operation not permitted at /usr/local/cpanel/Cpanel/Autodie/CORE/chmod.pm line 48. Cpanel::Autodie::chmod(420, GLOB(0x2aa8370)) called at /usr/local/cpanel/Cpanel/Transaction/File/Base.pm line 210 Cpanel::Transaction::File::Base::_set_permissions(GLOB(0x2aa8370), 420, undef) called at /usr/local/cpanel/Cpanel/Transaction/File/Base.pm line 140 Cpanel::Transaction::File::Base::new("Cpanel::Transaction::File::Raw", "path", "/home/osha/public_html/user/.htaccess", "permissions", 420, "restore_original_permissions", 1) called at /usr/local/cpanel/Cpanel/WebServer/Supported/apache/Htaccess.pm line 191 Cpanel::WebServer::Supported::apache::Htaccess::_internal_set_handler(Cpanel::WebServer::Supported::apache::Htaccess=HASH(0x17d3b60), "handler", Cpanel::WebServer::Supported::apache::Handler::suphp=HASH(0x28d43c8), "vhost", "user.domain.tld", "userdata", Cpanel::WebServer::Userdata=HASH(0x23117b0), "package", ...) called at /usr/local/cpanel/Cpanel/WebServer/Supported/apache/Htaccess.pm line 212 Cpanel::WebServer::Supported::apache::Htaccess::__ANON__() called at /usr/local/cpanel/Cpanel/AccessIds/ReducedPrivileges.pm line 96 eval {...} called at /usr/local/cpanel/Cpanel/AccessIds/ReducedPrivileges.pm line 96 Cpanel::AccessIds::ReducedPrivileges::call_as_user(CODE(0x282b1b0), 523, 536) called at /usr/local/cpanel/Cpanel/WebServer/Supported/apache/Htaccess.pm line 217 Cpanel::WebServer::Supported::apache::Htaccess::set_handler(Cpanel::WebServer::Supported::apache::Htaccess=HASH(0x17d3b60), "package", "ea-php56", "lang", Cpanel::ProgLang::Supported::php=HASH(0x283f260), "vhost", "user.domain.tld", "userdata", ...) called at /usr/local/cpanel/Cpanel/WebServer/Supported/apache.pm line 933 Cpanel::WebServer::Supported::apache::__ANON__(Cpanel::Exception::IO::ChmodError=HASH(0x2b0f3f8)) called at /usr/local/cpanel/3rdparty/perl/528/lib/perl5/cpanel_lib/Try/Tiny.pm line 118 Try::Tiny::try(CODE(0x2aa7f80), Try::Tiny::Catch=REF(0x2aa7500)) called at /usr/local/cpanel/Cpanel/WebServer/Supported/apache.pm line 939 Cpanel::WebServer::Supported::apache::_update_vhost(Cpanel::WebServer::Supported::apache::Handler::suphp=HASH(0x28d43c8), Cpanel::WebServer::Supported::apache::Htaccess=HASH(0x17d3b60), Cpanel::WebServer::Userdata=HASH(0x23117b0), Cpanel::WebServer::Supported::apache::Handler::fpm=HASH(0x2aa75f0), "user.domain.tld", Cpanel::ProgLang::Supported::php=HASH(0x283f260), "ea-php56", "ea-php56", ...) called at /usr/local/cpanel/Cpanel/WebServer/Supported/apache.pm line 916 Cpanel::WebServer::Supported::apache::set_vhost_lang_package(Cpanel::WebServer::Supported::apache=HASH(0x2847a68), "vhost", "user.domain.tld", "lang", Cpanel::ProgLang::Supported::php=HASH(0x283f260), "package", "ea-php56", "userdata", ...) called at /usr/local/cpanel/Cpanel/WebServer.pm line 450 Cpanel::WebServer::__ANON__(Cpanel::Exception::IO::ChmodError=HASH(0x2a6be10)) called at /usr/local/cpanel/3rdparty/perl/528/lib/perl5/cpanel_lib/Try/Tiny.pm line 118 Try::Tiny::try(CODE(0x2847d38), Try::Tiny::Catch=REF(0x2847c48)) called at /usr/local/cpanel/Cpanel/WebServer.pm line 455 Cpanel::WebServer::set_vhost_lang_package(Cpanel::WebServer=HASH(0x2834a60), "vhost", "user.domain.tld", "package", "ea-php73", "lang", Cpanel::ProgLang::Supported::php=HASH(0x283f260), "user", ...) called at /usr/local/cpanel/Cpanel/WebServer.pm line 529 Cpanel::WebServer::__ANON__() called at /usr/local/cpanel/3rdparty/perl/528/lib/perl5/cpanel_lib/Try/Tiny.pm line 97 eval {...} called at /usr/local/cpanel/3rdparty/perl/528/lib/perl5/cpanel_lib/Try/Tiny.pm line 88 Try::Tiny::try(CODE(0x2839d40), Try::Tiny::Catch=REF(0x28459b8)) called at /usr/local/cpanel/Cpanel/WebServer.pm line 535 Cpanel::WebServer::set_vhost_lang_packages(Cpanel::WebServer=HASH(0x2834a60), "user", "osha", "vhosts", ARRAY(0x2839a88), "lang", Cpanel::ProgLang::Supported::php=HASH(0x283f260), "package", ...) called at /usr/local/cpanel/Cpanel/PHP/Vhosts.pm line 96 Cpanel::PHP::Vhosts::setup_vhosts_for_php(ARRAY(0x24635e0)) called at /usr/local/cpanel/Cpanel/PHP/Vhosts.pm line 240 Cpanel::PHP::Vhosts::php_set_vhost_versions_as_root(__CPANEL_HIDDEN__, __CPANEL_HIDDEN__, HASH(0x1bcb318), 0) called at /usr/local/cpanel/Cpanel/Admin/Modules/Cpanel/multilang.pm line 60 eval {...} called at /usr/local/cpanel/Cpanel/Admin/Modules/Cpanel/multilang.pm line 60 Cpanel::Admin::Modules::Cpanel::multilang::UPDATE_VHOST_CPANEL(Cpanel::Admin::Modules::Cpanel::multilang=HASH(0x1b8b608), "ea-php73", "user.domain.tld") called at /usr/local/cpanel/Cpanel/Admin/Base.pm line 618 eval {...} called at /usr/local/cpanel/Cpanel/Admin/Base.pm line 618 Cpanel::Admin::Base::run("Cpanel::Admin::Modules::Cpanel::multilang", "username", undef, "uid", 523, "function", "UPDATE_VHOST_CPANEL", "args", ...) called at /usr/local/cpanel/Cpanel/AdminBin/Server/Backend.pm line 131 eval {...} called at /usr/local/cpanel/Cpanel/AdminBin/Server/Backend.pm line 129 Cpanel::AdminBin::Server::Backend::run_admin_module("perl_module", "Cpanel::Admin::Modules::Cpanel::multilang", "uid", 523, "args", ARRAY(0x1b20b20), "function", "UPDATE_VHOST_CPANEL", ...) called at /usr/local/cpanel/Cpanel/AdminBin/Server.pm line 220 Cpanel::AdminBin::Server::_request_handler(Cpanel::AdminBin::Server=HASH(0x1b20418), HASH(0x1b20670), undef) called at /usr/local/cpanel/Cpanel/AdminBin/Server.pm line 114 Cpanel::AdminBin::Server::__ANON__() called at /usr/local/cpanel/Cpanel/Try.pm line 187 eval {...} called at /usr/local/cpanel/Cpanel/Try.pm line 187 Cpanel::Try::try(CODE(0x1b20520), "Cpanel::Exception::ProcessNotRunning", CODE(0x1b20658)) called at /usr/local/cpanel/Cpanel/AdminBin/Server.pm line 117 Cpanel::AdminBin::Server::handle_cpwrapd_request(Cpanel::AdminBin::Server=HASH(0x1b20418), HASH(0x1b20208)) called at /usr/local/cpanel/Cpanel/Server.pm line 2302 Cpanel::Server::handle_cpwrapd_connection(Cpanel::Server=HASH(0x18a2318)) called at cpsrvd.pl line 1771 cpanel::cpsrvd::_handle_unix_socket_connection("handle_cpwrapd_connection") called at cpsrvd.pl line 1085 cpanel::cpsrvd::script() called at cpsrvd.pl line 425 The WHM interface displays PHP5.6 after this, but website doesn't render until PHP5.6 is specifically reassigned to the site. What the heck is going on?