Hi porferry,
Welcome to the forums!
It all looks quite ok 
There is no ‘way around’ not having a working connection, the problem needs to be troubleshot and solved.
As you might have guessed, the (missing) reverse DNS does not interfere with the connection.
How intermittent is your connection? If you run a ping to your Yunohost, does it drop many packages?
First things that come to mind are, in no particular order:
- duplicate IP’s on the network
- ‘complex’ networks, with loops where packages get lost
- cable/connector problems
- fail2ban blocking your connection (it has happened before)
How handy are you with the computers and appliances (router/switch/…) in your network? How is your Yunohost connected to the LAN?