The currency changes randomly

The currency changes randomly, unlike the settings I set, and I changed Currency storage with all its options, and no change occurred. Once I cleared the site’s cache, it worked properly. Then, in less than an hour, the currencies appear randomly on every page, and every time a different currency appears.

To summarize, I want a specific way to cancel the automatic currency conversion and it is only converted manually, as I want the default currency to be the one that appears when the site opens for all pages