Repeating event does not show in Calendar app on Nextcloud website

Steps to reproduce

I have a repeating calendar event with an event on July 7th. This event is not show in the Calendar app on Nextcloud website. On my Android smartphone the event is shown.

Here's the event:

BEGIN:VCALENDAR
VERSION:2.0
PRODID:DAVx5/3.3.11-gplay ical4j/3.0.24 (org.withouthat.acalendarplus)
BEGIN:VEVENT
DTSTAMP:20210615T124331Z
UID:66e04267-3d31-4755-89b6-af7780aab054
SEQUENCE:7
SUMMARY:Serientermin
DTSTART;TZID=Europe/Berlin:20201110T153000
DTEND;TZID=Europe/Berlin:20201110T163000
RRULE:FREQ=MONTHLY;UNTIL=20370101T000000Z;BYMONTHDAY=10
RDATE;TZID=Europe/Berlin:20210816T100000,20210510T140000,20210707T103000
EXDATE;TZID=Europe/Berlin:20210410T153000,20210810T153000,20210510T153000,2
 0210610T153000,20210710T153000
CLASS:PUBLIC
CREATED:20201109T085408Z
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20210615T124331Z
UID:66e04267-3d31-4755-89b6-af7780aab054
RECURRENCE-ID;TZID=Europe/Berlin:20201210T153000
SEQUENCE:1
SUMMARY:Serientermin
DTSTART;TZID=Europe/Berlin:20201207T103000
DTEND;TZID=Europe/Berlin:20201207T113000
CLASS:PUBLIC
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20210615T124331Z
UID:66e04267-3d31-4755-89b6-af7780aab054
RECURRENCE-ID;TZID=Europe/Berlin:20210110T153000
SEQUENCE:1
SUMMARY:Serientermin
DTSTART;TZID=Europe/Berlin:20210112T153000
DTEND;TZID=Europe/Berlin:20210112T163000
CLASS:PUBLIC
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20210615T124331Z
UID:66e04267-3d31-4755-89b6-af7780aab054
RECURRENCE-ID;TZID=Europe/Berlin:20210210T153000
SEQUENCE:1
SUMMARY:Serientermin
DTSTART;TZID=Europe/Berlin:20210210T140000
DTEND;TZID=Europe/Berlin:20210210T150000
CLASS:PUBLIC
END:VEVENT
BEGIN:VTIMEZONE
TZID:Europe/Berlin
LAST-MODIFIED:20201010T011803Z
BEGIN:DAYLIGHT
TZNAME:CEST
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
DTSTART:19810329T020000
RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
END:DAYLIGHT
BEGIN:STANDARD
TZNAME:CET
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
DTSTART:19961027T030000
RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
END:STANDARD
END:VTIMEZONE
END:VCALENDAR

I only changed the original title and left the rest as it was.

Some months ago I experienced the same issue with another event. Unfortunately I do not know anymore what event so I cannot look it up in the database.

Calendar app

Calendar app version: (see apps admin page, e.g. 2.0.1)

CalDAV-clients used: DAVx5

Client configuration

Browser: Brave, Chrome

Operating system: Windows

Server configuration

Operating system: Debian 10

Web server: Apache

Database: MariaDB

PHP version: 7.4

Nextcloud Version: 21.0.2

Updated from an older installed version or fresh install: updated

If the rest of the information you ask for in bug reports (list of activated apps, configuration...) is needed please let me know.

Start by reproducing the missing July 7 occurrence in the Calendar app using the supplied VCALENDAR data, DAVx5 client, and listed Nextcloud configuration. Compare the website's displayed recurring events with the Android result; done means the July 7 event is visible in the web calendar without breaking the other recurrence exceptions.