Currently the actions menu button is also shown when the actions slot is empty. Clicking on the button then does not do anything (besides showing the tiny arrow below).
Code like this
<Modal v-if="modalOpen"
@close="closeModal"
>
<span>Modal content.</span>
</Modal>
leads to a Modal like this (see the three-dot actions menu button at the right top):

Already fixed :)
https://github.com/nextcloud/nextcloud-vue/pull/391
Sorry I didn鈥檛 find this.
No worries ! :hugs: