Error: HTML5 compatible browser

Issue: Displays “Please use on HTML5 compatible browser.”
The user mentioned: “Happens Sporadically. Sometimes I can refresh once and it fixes it. Other times I can refresh ten times. No luck.”
User’s Device: 2023 MacBook Air with Safari

I have done some research on the compatible browsers for PDFjs Express, and found that the user’s browser is compatible, but not sure why facing this issue.

Attaching an image of where we have placed PDFjs Express.

Thanks