It looks good to me but I haven't been able to test it myself.

I made a few small changes. The computed position value should be used in all places. Then it works as expected.

Sorry for posting here but it seems closely related:
For a range with min=0 and max=5, when the stored value is 0, it does not display the value zero (neither on the slider nor in the label) but the default value.

It seems to me that this is a JS zero/null confusion caused by the code changes above.

The original line 80 in RangeInput.vue explicitly compared with null, where the change now only uses this.value which is falseish also when it contains the number zero.

I tried to test/fix it in my kirby installation but apparently the vue sources are not directly used but need some build step I have no idea how to perform.

Thank you @plan44, i have fixed the issue on #2549