PHP version

We have a website which has been using this theme since 2017. It doesn't look like the theme has been updated since then. It is beginning to develop issues with newer PHP versions, and I am troubleshooting and looking for the cause. I haven't finished running through plugins but just switched to Twenty Twenty and it had no problem changing the PHP version to one still supported. This is not a good sign. We do not want to switch. Is Catch Themes making sure this theme has stayed current with the current WordPress core and PHP versions. When will an updated version of the theme be available? Please advise.