Help, not working with minimum function on phone browser

The Minimum/Maximum Amount for WooCommerce is not worked for Safari on my phone. I have set “Amount limits” is Minimum, and the “Amount types” is quantity. and i set the “Checkout options” that Prevent users from placing the order with wrong amounts” and “Prevent users from reaching the checkout page on wrong min/max amount” into enable.

Here is the listing detail:

I created 2 variations (variations A, variations B) on my listing, and set the different minimum quantity of each variation,  variations A is 5, variations B is 20, and i set the default minimum quantity to 5 on my listing.

but when i open the listing on my phone, i can still use 5 to order variations B, which the minimum quantity is 20.  So it is the matter.

But the it is work on my PC browser, there is no such problem on PC brower.