It’s very strange that the header doesn’t load with some products. I have made a video about this issue. Clearing the cache temporarily solves the problem, but it returns after some time.
The issue is that this can happen with any product. Please help me with this. You can visit any of the URLs shown in the video to see the problem.
You should disable Mobile DOM optimization (experimental) option in Theme Settings > Performance > Other and double check. https://prnt.sc/NEd76ZnsfTVD
The thing is the Mobile DOM optimization (experimental) option works well only with the separate cache, in your case it is disabled so you have such an issue.
I just talked to SiteGround support about their speed optimization plugin. I mentioned that the Mobile DOM Optimization (experimental) feature requires a separate cache option, which is unavailable in your plugin. I also shared a screenshot for reference: https://postimg.cc/FdhpHP0s.
They told me they have a similar feature called Browser-specific Caching. (Generate caching separately for different browsers. Enable this feature only if you’re experiencing issues with plugins generating mobile versions of your website or other similar functionality.)
Now I need your confirmation. Will this feature work? Right now, I have enabled both “Mobile DOM Optimization (experimental)” from the theme and “Browser-specific Caching” from the plugin. Please advise and help.