PROPFIND 405 Method Not Allowed on route remote.php/webdav

I installed OwnCloud 9.1.3 on Debian Jessie with the OwnCloud's apt repo, v9.1. Whenever the web interface reloads, PROPFIND 405 Method Not Allowed error shows up.

Steps to reproduce
1. Install OwnCloud 9.1.3 with apt repo
2. Set up OwnCloud through the web wizard
3. Log in
4. Reload / Click on sample directories
5. PROPFIND 405 shows up in browser console; breadcrumb shows nothing except the home icon; no files in the file listing container

Expected behaviour
Should show a list of files when user press refresh button / click on a directory.

Actual behaviour
PROPFIND 405 shows up in browser console; breadcrumb shows nothing except the home icon; no files in the file listing container

Screeshot:

Server configuration
Operating system: Debian Jessie
Web server: Apache 2.4.10
Database: MySQL 5.7.10
PHP version:
ownCloud version (see ownCloud admin page): 9.1.3
Updated from an older ownCloud or fresh install: fresh install
Special configuration (external storage, external authentication, reverse proxy, server-side-encryption): none

ownCloud log (data/owncloud.log)

{"reqId":"0qlrI3jqKPM0VMgKstqh","remoteAddr":"45.64.241.52","app":"PHP","message":"Cannot modify header information - headers already sent by (output started at \/var\/www\/owncloud\/apps\/dav\/appinfo\/v1\/webdav.php:51) at \/var\/www\/owncloud\/3rdparty\/sabre\/http\/lib\/Sapi.php#58","level":3,"time":"2017-01-28T05:38:53+00:00","method":"GET","url":"\/owncloud\/remote.php\/webdav","user":"jnl_admin"}
{"reqId":"Jt\/2jv\/flemAUADNXDa8","remoteAddr":"45.64.241.52","app":"DeleteOrphanedItems","message":"0 orphaned system tag relations deleted","level":0,"time":"2017-01-28T06:18:06+00:00","method":"GET","url":"\/owncloud\/cron.php","user":"--"}
{"reqId":"Jt\/2jv\/flemAUADNXDa8","remoteAddr":"45.64.241.52","app":"DeleteOrphanedItems","message":"0 orphaned user tag relations deleted","level":0,"time":"2017-01-28T06:18:06+00:00","method":"GET","url":"\/owncloud\/cron.php","user":"--"}
{"reqId":"Jt\/2jv\/flemAUADNXDa8","remoteAddr":"45.64.241.52","app":"DeleteOrphanedItems","message":"0 orphaned comments deleted","level":0,"time":"2017-01-28T06:18:06+00:00","method":"GET","url":"\/owncloud\/cron.php","user":"--"}
{"reqId":"Jt\/2jv\/flemAUADNXDa8","remoteAddr":"45.64.241.52","app":"DeleteOrphanedItems","message":"0 orphaned comment read marks deleted","level":0,"time":"2017-01-28T06:18:06+00:00","method":"GET","url":"\/owncloud\/cron.php","user":"--"}
{"reqId":"Qk2x37F6E9v9iXfwimUJ","remoteAddr":"45.64.241.52","app":"DeleteOrphanedSharesJob","message":"0 orphaned share(s) deleted","level":0,"time":"2017-01-28T06:21:16+00:00","method":"GET","url":"\/owncloud\/cron.php","user":"--"}

Note:
- No PROPFIND in apache2/access.log
- No error in apache2/error.log
- No error in php-error.log

Integrity status for oC9+

No error has been found.

Unfortunately the search function of the forums seems to not work. With that you could find the following FAQ containing all needed infos about this environmental / webserver issue: