Invitation doesn't contain reminder

Steps to reproduce

1. Setup a invitation with the Nextcloud calendar
2. make sure to set a reminder

3. send out the invitation

Expected behavior

The recipient gets a invitation with the reminder set

Actual behaviour

The recipient gets a invitation without a reminder:

BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Sabre//Sabre VObject 4.4.2//EN
CALSCALE:GREGORIAN
METHOD:REQUEST
BEGIN:VTIMEZONE
TZID:Europe/Oslo
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:19700329T020000
RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:19701025T030000
RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
CREATED:20230717T212315Z
LAST-MODIFIED:20230717T212836Z
SEQUENCE:2
UID:9f250548-4f25-4b92-b004-7ac7e3f188a2
DTSTART;TZID=Europe/Oslo:20230721T063000
DTEND;TZID=Europe/Oslo:20230721T070000
STATUS:CONFIRMED
SUMMARY:Test4
ATTENDEE;CN=bjoern@nextcloud.com;CUTYPE=INDIVIDUAL;PARTSTAT=NEEDS-ACTION;RO
 LE=REQ-PARTICIPANT;RSVP=TRUE:mailto:bjoern@nextcloud.com
ORGANIZER;CN=Björn Schießle:mailto:bjoern.schiessle@nextcloud.com
DTSTAMP:20230717T212836Z
END:VEVENT
END:VCALENDAR

Calendar app version

No response

CalDAV-clients used

No response

Browser

No response

Client operating system

No response

Server operating system

No response

Web server

None

Database engine version

None

PHP engine version

None

Nextcloud version

No response

Updated from an older installed version or fresh install

None

List of activated apps

No response

Nextcloud configuration

No response

Web server error log

No response

Log file

No response

Browser log

No response

Additional info

No response

Reproduce the issue with a Nextcloud calendar invitation and inspect the generated VCALENDAR data shown in the report. Trace the invitation-generation entry point and verify that a configured reminder is included in the invitation received by the recipient.