Public calendar doesn't exist after upgrade to Nextcloud Hub 26 Winter

[DesertCookie]

Steps to reproduce

1. Update AIO to Nextcloud Hub 26 Winter (33.0.2) from the latest Nextcloud Hub 25 update.
2. Visit a previously available public calendar URL.

Expected behavior

The calendar appears instead of saying it does not exist.

Actual behavior

The page shows (German):

Öffentlicher Kalender existiert nicht
Vielleicht wurde die Freigabe gelöscht oder ist abgelaufen?

Calendar app version

6.3.0-rc.1

CalDAV-clients used

No response

Browser

Firefox 147 and others

Client operating system

Fedora Linux and others

Server operating system

unRAID

Web server

None

Database engine version

None

PHP engine version

None

Nextcloud version

33.0.2

Updated from an older installed version or fresh install

None

List of activated apps

Nextcloud configuration

Web server error log

Log file

Browser log

Uncaught TypeError: can't access property "getApi", this.$refs.fullCalendar is null
    mounted CalendarGrid.vue:245
    d index.js:27
    c index.js:40
    setTimeout handler*c index.js:35
    setTimeout handler*u index.js:61
    mounted CalendarGrid.vue:244
    rt runtime-core.esm-bundler.js:3089
    d runtime-core.esm-bundler.js:199
    c runtime-core.esm-bundler.js:206
    __weh runtime-core.esm-bundler.js:3069
    k runtime-core.esm-bundler.js:385
    w runtime-core.esm-bundler.js:427
    promise callback*y runtime-core.esm-bundler.js:322
    C runtime-core.esm-bundler.js:336
    ea runtime-core.esm-bundler.js:7535
    scheduler runtime-core.esm-bundler.js:891
    scheduler reactivity.esm-bundler.js:1924
    trigger reactivity.esm-bundler.js:267
    _ reactivity.esm-bundler.js:325
    notify reactivity.esm-bundler.js:616
    trigger reactivity.esm-bundler.js:590
    set value reactivity.esm-bundler.js:1529
    x vue-router.js:1389
    C vue-router.js:1317
    promise callback*C vue-router.js:1305
    b vue-router.js:1258
    install vue-router.js:1505
    use runtime-core.esm-bundler.js:4164
    <anonymous> main.js:52
    <anonymous> calendar-main.js:2
    <anonymous> calendar-main.js:2
CalendarGrid.vue:245:5

Uncaught (in promise) TypeError: can't access property "findAllCalendars", c() is undefined
    p caldavService.js:66
    backgroundSyncJob Calendar.vue:299
    setInterval handler*created Calendar.vue:297
    d runtime-core.esm-bundler.js:199
    c runtime-core.esm-bundler.js:206
    $t runtime-core.esm-bundler.js:3930
    Xt runtime-core.esm-bundler.js:3847
    Qa runtime-core.esm-bundler.js:8238
    l runtime-core.esm-bundler.js:8161
    Va runtime-core.esm-bundler.js:8087
    M runtime-core.esm-bundler.js:6011
    N runtime-core.esm-bundler.js:5977
    g runtime-core.esm-bundler.js:5476
    effect runtime-core.esm-bundler.js:6205
    run reactivity.esm-bundler.js:239
    runIfDirty reactivity.esm-bundler.js:277
    d runtime-core.esm-bundler.js:199
    w runtime-core.esm-bundler.js:408
    promise callback*y runtime-core.esm-bundler.js:322
    C runtime-core.esm-bundler.js:336
    ea runtime-core.esm-bundler.js:7535
    scheduler runtime-core.esm-bundler.js:891
    scheduler reactivity.esm-bundler.js:1924
    trigger reactivity.esm-bundler.js:267
    _ reactivity.esm-bundler.js:325
    notify reactivity.esm-bundler.js:616
    trigger reactivity.esm-bundler.js:590
    set value reactivity.esm-bundler.js:1529
    x vue-router.js:1389
    C vue-router.js:1317
    promise callback*C vue-router.js:1305
    b vue-router.js:1258
    install vue-router.js:1505
    use runtime-core.esm-bundler.js:4164
    <anonymous> main.js:52
    <anonymous> calendar-main.js:2
    <anonymous> calendar-main.js:2
5 caldavService.js:66:9
    p caldavService.js:66
    backgroundSyncJob Calendar.vue:299
    (Async: setInterval handler)
    created Calendar.vue:297
    d runtime-core.esm-bundler.js:199
    c runtime-core.esm-bundler.js:206
    $t runtime-core.esm-bundler.js:3930
    Xt runtime-core.esm-bundler.js:3847
    Qa runtime-core.esm-bundler.js:8238
    l runtime-core.esm-bundler.js:8161
    Va runtime-core.esm-bundler.js:8087
    M runtime-core.esm-bundler.js:6011
    N runtime-core.esm-bundler.js:5977
    g runtime-core.esm-bundler.js:5476
    effect runtime-core.esm-bundler.js:6205
    run reactivity.esm-bundler.js:239
    runIfDirty reactivity.esm-bundler.js:277
    d runtime-core.esm-bundler.js:199
    w runtime-core.esm-bundler.js:408
    (Async: promise callback)
    y runtime-core.esm-bundler.js:322
    C runtime-core.esm-bundler.js:336
    ea runtime-core.esm-bundler.js:7535
    scheduler runtime-core.esm-bundler.js:891
    scheduler reactivity.esm-bundler.js:1924
    trigger reactivity.esm-bundler.js:267
    _ reactivity.esm-bundler.js:325
    notify reactivity.esm-bundler.js:616
    trigger reactivity.esm-bundler.js:590
    set value reactivity.esm-bundler.js:1529
    x vue-router.js:1389
    C vue-router.js:1317
    (Async: promise callback)
    C vue-router.js:1305
    b vue-router.js:1258
    install vue-router.js:1505
    use runtime-core.esm-bundler.js:4164
    <anonym> main.js:52
    <anonym> calendar-main.js:2
    <anonym> calendar-main.js:2

Additional info

The public calendar link did work right before the update. I verified it is the correct link by copying (while logged in) from the calendar.