Sale price for USD saves as empty and other odd issue

Hi,

I have an issue where the sale price value for USD is empty (doesnt save). The regular USD price is set at $69, yet it shows a sale price still of $48.09 when there is no USD fixed sale price value except on the base/default AUD sale price of $75.90 AUD

It looks to be taking the AUD sale price, converting to USD and removing the 10% tax to get the USD sale price its showing.
Tax is removed for overseas as configured on the site – so that 10% removal is fine.

Here is the testing to date;
Base AUD currency has a Sale price There is NO sale price for USD
USD Converts AUD sale price and displays this as the USD sale price (even though no sale price entered in USD) Enabled the “Don’t use exchange rate” USD—> this makes the USD sale price show as $0.00

AUD and USD both have sale price (turned off the option “dont use exchange rate”)
Pricing is correct for both AUD and USD – seems to only save USD sale price when the base AUD rate has a sale price entry too.

AUD—> regular price only > Correct conversion price for USD
USD Sale price entered > Does not save and therefore ignores the USD sale price and shows regular USD price
The USD sale price is erased on save variations, hence showing regular USD price as the sale price no longer exists

I have disabled all plugins except the following and switched to default Twenty Twenty-Three theme;
CURCY
Redis Object Cache
Woocommerce
WP Bakery

Same issue – any ideas?

Thanks