Popup.vue render error

[estern1011]

In a project that's transitioning from Vue 2 to Vue 3 we decided to swap from @sum.cumo/vue-datepicker 5.0.0 to version 6.0.0 of this fork. When launching the page we had an issue with this line:

vue-datepicker/src/components/Popup.vue

Line 98 in ca0bb3e

return h('div', this.$slots.default()[0].children.default())

.
We got an error that default in this.$slots.default() was not a function. We were able to fix this issue locally by changing the line to return h('div', this.$slots.default[0].children.default());
Is this because of our Vue 3 transition, or is this an issue with the Popover component? We were confused because we'd expect the repository's demo page to not work correctly if this was an issue with the component itself, but that page works.
If it's an issue with the Popover component, we're happy to submit a PR with our change!