I have installed Ubuntu Server 18.04 with apache2 (one website and owncloud), samba etc. Couple days ago everything was working fine. I could open website, cloud and connect to server with ssh. Something happened and now from my computer I can not access to ubuntu server with ssh also website and cloud not working. I checked from other ip and everything works fine. also with local ip it works. Looks like Ubuntu blocking or not responding only one IP.
1. Never touched iptables but just in case I reset it
2. /etc/hosts.deny is clean

P.S. It happened after I upload a large (2Gb) file in ownCloud. Couple month ago I had this type of problem bot I do not remember how i fixed it