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I checked and there was a JS error occured. https://i.imgur.com/7DYQyNW.png
I need to login to check it, if you want please send the staff to me. I will check it.
This is an accepted solution.
Yes, a member of LitExtension was able to look at the code and show me where the error was. I’m my case, it was due to some languages I modified regarding product pages. However, I think this issue can arise from different types of Java Script errors. So, it’s best to ask a developer if you aren’t confident that you can locate the error yourself.