Is there still no fix for this? I’ve purchased this theme for many of my clients sites in the past year or 2, and now I’m concerned about this issue. This has just happened to a site I just launched a week ago. I did what the OP did and deactivated the core, refreshed customizer, clicked “discard change”, then reactivated the core and it seems to have worked.
I worry if this has caused any other issues that I won’t see until I go through the entire site. Luckily it happened on staging and not live. I’m afraid to implement this to live. I’d like to find out if this is being resolved still.