Loved until WP core update 5.3.2 where it resetted

Very much loved that theme and had a child theme in order to keep any customizations during updates.
After WP core update 5.3.2, and the version before that, all theme customizations are lost.
Either theme update or WP update, the customizations of the child theme are lost.
Pitty, because I have been using this theme for at least 2 years and it served it purpose well.