Just for info - I am not having any issues with 19.5 RCs and MySQL as the DB. Same setup as I’ve used for years is working fine - I presume you’re referring to it by IP in your advanced_settings.xml?
(My MySQL install is actually mariadb official in a docker - some info on that here: Update on MariaDB & CoreElec - as there have been some issues with mariadb and Kodi…)
If you roll back to 19.4 does it work?
<videodatabase>
<type>mysql</type>
<host>192.168.1.72</host>
<port>3306</port>
<user>xx</user>
<pass>xx</pass>
<name>kodi_video_adults</name>
</videodatabase>