Cannot write to some calendars from Thunderbird


I have a strange issue where I can sync and write to some calendars hosted on Owncloud from Thunderbird (version 45.3.0) Lightning (version 4.7.4), but not others.

I have two users on my owncloud, both with multiple calendars activated.
The ones from the one user I can write to from Thunderbird without issues; the ones from the other user fail with a 404 message in the thunderbird log.
Dismissing reminders for events gives a replay action failed-message in the thunderbird log.
More details on both below.

I can create events without problem for the same user from my android phone.

I couldn't really find any relevant cases online after a thorough search; so I am really curious to figure what is going on. I'm happy to supply more information as needed to fix this issue.

Steps to reproduce
1. Setup calendars in Thunderbird to sync with calendars on owncloud
2. Create event in Thunderbird for Calendar; save and close
3. Event does not appear in calendar

Expected behaviour
Event is created on the calendar hosted at Owncloud.

Actual behaviour
Event is not created; the error log in thunderbird indicates (anonomised; and cut down a bit):

Timestamp: 01/11/16 12:57:08
Error: CalDAV: Unexpected status adding item to xxx: 404
PRODID:-// Mozilla Calendar V1.1//EN 



Source File: file:///home/***/.thunderbird/hwf3mper.default/extensions/%7Be2fda1a4-762b-4020-b5ad-a41df1933103%7D/components/calDavCalendar.js
Line: 699

Steps to reproduce
1. Setup calendars in Thunderbird to sync with calendars on owncloud
2. Dismiss reminder for event

Expected behaviour
Event reminder is dismissed and this is registered by the server, and no new reminders for the event will be popped up.

Actual behaviour
Dismiss is not registered, and popups keep coming up for the event.
Error log in Thunderbird indicates (anonomised):

Timestamp: 31/10/16 00:01:19
Error: [calCachedCalendar] replay action failed: null, uri=https://cloud.xxxx.xx/remote.php/dav/calendars/nescivi/personal/, result=2147500037, op=[xpconnect wrapped calIOperation]
Source File: file:///home/****/.thunderbird/hwf3mper.default/extensions/%7Be2fda1a4-762b-4020-b5ad-a41df1933103%7D/calendar-js/calCachedCalendar.js
Line: 327

Server configuration
Operating system: Debian 3.2.73 (jessie)
Web server: apache2
Database: mysql
PHP version: 5.6.27
ownCloud version (see ownCloud admin page):
Updated from an older ownCloud or fresh install: updated
Special configuration (external storage, external authentication, reverse proxy, server-side-encryption):

ownCloud log (data/owncloud.log)

Please paste possible errors in the following code block, see for more info

Integrity status for oC9+

Integrity checker has been disabled. Integrity cannot be verified.

I didn't see relevant errors or other messages in the owncloud.log, that is why I didn't paste it in here.

After a lot of searching online, it seems that the problem I ran into is related to this one:

I had a special character (a !) in my password, which seems to have caused the problem. I have changed the password and now I can write to the calendars.