US Customary to Metric Buttons Not Working

We have the WP Recipe Maker Premium – Elite Bundle plugin and have been receiving a number of complaints from users that the US Customary to Metric Buttons are not working. We have found that they do work for some users and browsers and not for others. For example, they work on my Chrome Browser but not on my Microsoft Edge browser. For another they do not work on most of his browsers (Chrome, Edge, or Firefox) but do work on Opera. He is located in Florida. I am located in Maine. I have cleared all the caches, but no luck. However, the buttons do work on the Print Recipe pages. Any ideas?

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