After restart nextcloud file permission error

After a reboot of the vps I can’t access nextcloud. It says that config dir is not writable. Directories are nginx:nginx, it also is configured that way for nginx en php-fpm. I don’t know why after rebooting it is giving problems. No error can be found in logs.
Don’t know what could be the problem. Any thoughts?

Nextcloud version:
Operating system and version: CentOs Linux 7
Apache or nginx version: nginx 1.10.2
PHP version (eg, 5.6): 7.1.8
Is this the first time you’ve seen this error?: Yes

SELinux! This guide is a good point to start: