v1.5のVuetifyでv-btnのloading,disabledが反映されない

nuxt + TypeScriptでPWAを開発しています。
その中で期待通りの動作をしないことがあったためこちらで質問させて頂きます
該当コンポーネントファイルは以下です

vue
1<template>
2  <v-layout row>
3    <v-flex>
4      <v-card>
5        <v-img
6          src="https://cdn.vuetifyjs.com/images/lists/ali.png"
7          height="300px"
8        >
9          <v-layout column fill-height>
10            <v-card-title>
11              <v-btn dark icon to="/">
12                <v-icon>chevron_left</v-icon>
13              </v-btn>
14
15              <v-spacer></v-spacer>
16
17              <v-btn dark icon class="mr-3">
18                <v-icon>edit</v-icon>
19              </v-btn>
20            </v-card-title>
21
22            <v-spacer></v-spacer>
23
24            <v-card-title class="white--text pl-5 pt-5">
25              <div class="display-1 pl-5 pt-5">
26                <p>{{ deviceData.hostname }} ({{ deviceData.ipAddress }})</p>
27                <div v-if="isUpdating">
28                  <v-chip color="orange" text-color="white">
29                    <v-avatar>
30                      <v-icon>autorenew</v-icon>
31                    </v-avatar>
32                    Checking
33                  </v-chip>
34                </div>
35                <div v-else>
36                  <v-chip color="green" text-color="white">
37                    <v-avatar>
38                      <v-icon>check_circle</v-icon>
39                    </v-avatar>
40                    Alive
41                  </v-chip>
42                </div>
43              </div>
44            </v-card-title>
45          </v-layout>
46        </v-img>
47
48        <v-list two-line>
49          <v-list-tile>
50            <v-list-tile-action>
51              <v-icon color="indigo">important_devices</v-icon>
52            </v-list-tile-action>
53
54            <v-list-tile-content>
55              <v-list-tile-title>{{ deviceData.deviceType }}</v-list-tile-title>
56              <v-list-tile-sub-title>Device Type</v-list-tile-sub-title>
57            </v-list-tile-content>
58          </v-list-tile>
59
60          <v-list-tile>
61            <v-list-tile-action>
62              <v-icon color="indigo">edit</v-icon>
63            </v-list-tile-action>
64
65            <v-list-tile-content>
66              <v-list-tile-title>{{
67                deviceData.description
68              }}</v-list-tile-title>
69              <v-list-tile-sub-title>Description</v-list-tile-sub-title>
70            </v-list-tile-content>
71          </v-list-tile>
72
73          <v-divider inset></v-divider>
74
75          <v-list-tile v-for="(r, k) in deviceData.ezRequesterModels" :key="k">
76            <v-list-tile-action>
77              <v-icon color="indigo">reply</v-icon>
78            </v-list-tile-action>
79
80            <v-list-tile-content>
81              <v-list-tile-title>
82                {{
83                  `${r.protocol}://${deviceData.ipAddress}${r.parameterModel}`
84                }}</v-list-tile-title
85              >
86              <v-list-tile-sub-title
87                >EzRequester Parameter
88              </v-list-tile-sub-title>
89            </v-list-tile-content>
90
91            <v-list-tile-action>
92              <v-btn
93                dark
94                icon
95                :loading="ezRequesterSendingStates[k]"
96                :disabled="ezRequesterSendingStates[k]"
97                @click="sendRequest(k)"
98              >
99                <v-icon>redo</v-icon>
100              </v-btn>
101            </v-list-tile-action>
102          </v-list-tile>
103          <v-divider inset></v-divider>
104          <v-list-tile>
105            <v-list-tile-action>
106              <v-icon color="indigo">phone</v-icon>
107            </v-list-tile-action>
108            <v-list-tile-content>
109              <v-list-tile-title>Send ping manually </v-list-tile-title>
110              <v-list-tile-sub-title
111                >Check Status Manually</v-list-tile-sub-title
112              >
113            </v-list-tile-content>
114            <v-list-tile-action>
115              <v-btn
116                dark
117                icon
118                :loading="isUpdating"
119                :disabled="isUpdating"
120                @click="sendPing"
121              >
122                <v-icon>redo</v-icon>
123              </v-btn>
124            </v-list-tile-action>
125          </v-list-tile>
126        </v-list>
127      </v-card>
128    </v-flex>
129  </v-layout>
130</template>
131
132<script lang="ts">
133import { Vue, Component } from 'nuxt-property-decorator';
134import { DeviceData } from '@/types';
135import { deviceDataEmpty } from '@/mocks';
136import { vxm } from '@/store';
137import { Sleep } from '@/utilities';
138@Component
139export default class detail extends Vue {
140  public ipAddr: string = 'default';
141  public deviceData: DeviceData = deviceDataEmpty;
142  public isUpdating: boolean = false;
143  public ezRequesterSendingStates: boolean[] = [];
144  public p: string = 'ou';
145  created() {
146    // GET parameter はcreatedで取らないとエラー
147    this.ipAddr = this.$route.query.ip as string;
148    this.deviceData = vxm.devices.deviceMap.get(this.ipAddr);
149    for (let i = 0; i < this.deviceData.ezRequesterModels.length; ++i) {
150      this.ezRequesterSendingStates.push(false);
151    }
152  }
153  public async sendPing() {
154    this.isUpdating = true;
155    await Sleep(1000);
156    this.isUpdating = false;
157  }
158  public async sendRequest(i: number) {
159    this.ezRequesterSendingStates[i] = true;
160    await Sleep(1000);
161    this.ezRequesterSendingStates[i] = false;
162  }
163}
164</script>
165
166<style scoped></style>