VueJS 2: Child does not update on parent change (props)

When I update the parent's singleIssue variable, it does not get updated inside my <issue> component. I am passing it there using props. I have achieved this in other projects already, but I can't seem to get what I am doing wrong.

I have reduced my code to the relevant parts, so it is easier to understand.

IssueIndex.vue:

<template>
    <div class="issue-overview">
        <issue v-if="singleIssue" :issue="singleIssue"></issue>

        <v-server-table url="api/v1/issues" :columns="columns" :options="options" ref="issuesTable">
            <span slot="name" slot-scope="props">{{props.row.name}}</span>

            <div slot="options" slot-scope="props" class="btn-group" role="group" aria-label="Order Controls">
                <b-btn class="btn-success" v-b-modal.issueModal v- 
on:click="showIssue(props.row)">Show</b-btn>
            </div>
        </v-server-table>
    </div>
</template>

<script>
    export default {
        mounted() {
            let app = this;

            axios.get('api/v1/issues/')
                .then(response => {
                    app.issues = response.data;
                })
                .catch(e => {
                    app.errors.push(e);
                }); 
        },
        data: () => {
            return {
                issues: [],
                singleIssue: undefined,
                columns: ['name', 'creation_date', 'options'],
                options: {
                    filterByColumn: true,
                    filterable: ['name', 'creation_date'],
                    sortable: ['name', 'creation_date'],
                    dateColumns: ['creation_date'],
                    toMomentFormat: 'YYYY-MM-DD HH:mm:ss',
                    orderBy: {
                        column: 'name',
                        ascending: true
                    },
                    initFilters: {
                        active: true,
                    }
                }
            }
        },
        methods: {
            showIssue(issue) {
                let app = this;

                app.singleIssue = issue;

                // This gets the action history of the card
                axios.get('api/v1/issues/getCardAction/' + issue.id)
                    .then(response => {
                        app.singleIssue.actions = response.data;
                    })
                    .catch(error => {
                        // alert
                    });
            }
        }
    }
</script>

Issue.vue:

<template>
    <div>
        {{ issue }}
    </div>
</template>

<script>
    export default {
        props: ['issue']
    }
</script>

So after showIssue() is triggered, it will get actions for the issue. But after then, I can't see the actions in the issue component.

If I update the issue-model in the issue component using form inputs, it will also start showing the actions. So I assume it's just in a weird state where it needs a refresh.

Thanks in advance!