Reported for: WooCommerce Multilingual 3.4.2
Resolved in: WooCommerce Multilingual 3.4.3
On the orders list the orders placed in secondary currencies were showing prices with the default decimal separator instead of the one configured for the respective currency.
WooCommerce Multilingual allows setting custom decimal separators for prices in different currencies when using the multiple currencies mode.
This is fixed in WooCommerce Multilingual 3.4.3-beta1