Why do I have to update my node version if I am up to date?
Your node is not up to date: the latest release of Bitcoin Core is 0.19.1 which is a newer release than 0.19.0.1.

You appear to be using a RaspiBolt. The RaspiBolt project's FAQ addresses your question here: How to upgrade Bitcoin Core?.

Regarding the reachability, your best bet is likely to raise an issue on the project's GitHub page (which it appears that you have done already).
There are some issues asking about nodes being unreachable on the project's github page, but I don't know more about that.