Quantity buttons increase by 2

Hello, after updating to latest virtuemart 2.6.16 version, when I use the + butoon to increase quantity, from 1 goes to 3, 5, 7, etc.
Sometimes, when I press the + button it goes to 2 and with another click to 4,6, etc, ie there is an increment of 2 in each + step.
Is there a solution on this please ?

Hi,
check on default template behavior of that button.
Beside VM/VM3 is weird software and normal developers go away from it in last year.