Restriction on maximum weight (PayPal)

-- HikaShop version -- : 4.2.3
-- Joomla version -- : 3.9.15
-- PHP version -- : 7.3
-- Browser(s) name and version -- : N/A

Hi, I have instantiated 2 PayPal plugins with different configurations, one to be used for virtual goods and the other for physical goods.
To automatically present only the appropriated payment method, I set the physical goods plugin with minimum weight of 0.001 Kg and it appears only when there are physical goods. So far it's ok.
Then for the virtual goods plugin, I set maximum weight of 0 but it is not a valid value, then I set 0.0001 Kg and this restriction does not work: that plugin appears in checkout also for physical goods (e.g. with weight of 1 Kg).
What's wrong with that?
Thanks a lot

Giuse