Comparing the input type number of Bootstrap 4 whit the one from BootstrapVue i found some diferences:

When the input parses to a float as NaN the input is emptied and you loose the values.

I tested on Firefox and Chrome. Windows and Linux Mint.

I've made a JsFiddle comparing the two tipes of inputs.

I've tried my best to find where the input value is parsed to a float, but apparently is even before the input event.

https://jsfiddle.net/esron/kf3t4bvq/19/