Zend certified PHP/Magento developer

Category view – triple page-main CSS class

Vanilla Magento 2.4.3-p1, Mysql 8.0 (Percona), Elasticsearch 7.15.1, Varnish 6.5.2 on Ubuntu 20.04.3

Double checked PHP ext.:

$ composer check-platform-reqs –no-dev

Checking non-dev platform requirements for packages in the vendor dir

composer-plugin-api 2.1.0 success
ext-bcmath 7.4.3 success
ext-ctype 7.4.3 success
ext-curl 7.4.3 success
ext-dom 20031129 success
ext-fileinfo 7.4.3 success
ext-gd 7.4.3 success
ext-hash 7.4.3 success
ext-iconv 7.4.3 success
ext-intl 7.4.3 success
ext-json 7.4.3 success
ext-libxml 7.4.3 success
ext-mbstring 7.4.3 success
ext-openssl 7.4.3 success
ext-pcre 7.4.3 success
ext-pdo_mysql 7.4.3 success
ext-simplexml 7.4.3 success
ext-soap 7.4.3 success
ext-sockets 7.4.3 success
ext-sodium 7.4.3 success
ext-tokenizer 7.4.3 success
ext-xmlwriter 7.4.3 success
ext-xsl 7.4.3 success
ext-zip 1.15.6 success
lib-libxml 2.9.10 success
lib-openssl 1.1.1.6 success
php 7.4.3 success

My issue is that on category page view, CSS “page-main” class is tripled (assigned to 3 different divs). Can anybody point me at the right direction to get it fixed?