Thank you very much for it, I have looked through the source code.
I have found a possible solution, but I am not sure I recommend using it. Let me explain. The plugin uses a very special method to apply the sales to the products. Basically it sets a temporary variable (transient) with the on-sale products to the currently listed page, and then uses this variable to check if any of the listed items are on sale. There is no function/method within the plugin that is able to check if an item is on a global sale based on the product only, as it also requires this page transient to be present.
I had to extract these two functions from the plugin to a separate function, and also create a filter to add the 'fixed' price to the results list. Please use this solution with caution, it may not work in all cases.
Add this custom code to the functions.php in your theme/child theme directory (copy from line 3 only!). Before editing, please make sure to have a full site back-up just in case!Best,
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