How many Products View in shop – Drop Down displaying strangely

Hi there, for some reason the drop down to choose how many products to display per page, behaves strangely when you click on it. The drop down options appears way below the selector. Please can you take a look? I realise this is a conflict with the theme but the theme settings are required to display other elements in a modern way. I hope you guys can give me some css or php to correct the problem so that it’s compatible with the theme? It happens on two websites: https://swdgras.com/shop/ and https://oyoostyle.co.za/shop Thanks!

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