If you previously set the amount under "Set fixed amount" or "Fill Available up to a certain amount" to a value in a secondary currency (i.e. Euro), that currency symbol will apply to any other budget preset used, despite the values of those other presets being in the primary currency.

For example, the "Apply Budget Presets" dialog displays the budget preset amount for "Total expected recurring" in the primary currency (i.e. USD), but the currency symbol reflects the last currency set in the 'Fixed amount' or 'Fill Available up to a certain amount' budget preset fields (i.e. EUR).