We have taken on a new client’s webstore and have cloned it to our server. The clone seemed to work absolutely perfectly, however after doing some custom work, and creating a child theme for template overrides, we noticed that we cannot change the theme of the website. When changing it in design>configuration it gives no errors, says the value was saved but then the same theme that was previously selected is retained. I have tried rebuilding the whole site (clearing cache, setup upgrade, deploying content, literally the whole 9 yards) but no matter what I do I cant get the theme to change/update.
Whats weirder is core_config_data does have the correct theme id (as in the one I change it to) but the template changes made are not showing up.