We experienced some short interlude(s) in the recent day(s) when NG timed out for nefarious reasons. You might have hit that period of troublesome connections.
Eventually every problem vanished into thin air. Hopefully the bliss will last.
Thanks all for the comments. There is the Log4j vulnerability happening these days and associated attempts for exploits, so not strange there are periods of timeouts.
However this was not random/happening because of intermittency. I tested back and forth many times with and without VPN connection to the university when making posts. It happened every time with my provider and not with the VPN. Then the initial post in this thread was composed while on my providers network and would not post during multiple attempts to submit. I copied the content, switched to VPN and started the post over again and it posted immediately. After thinking for a minute I switched back to the providers network, did the DNS flush etc. described above, and did the next post only 12 minutes later on the provider's network - it was submitted successfully right away. I then edited the post again adding the success comment and it also was submitted without any delay.
I think you will find that the "connection" referred to is the internal connection from the reply php file to the database server - nothing to do with the IP or the internet.
Servers need to be regularly rebooted to clear errors etc.
The preview just shows what you have done - there is no writing to the database until the reply is actually posted.
Does my browser communicate directly with the database? If this is a negotiation between the NG site software and the database only, I do not see why flushing the DNS cache on my computer improved the situation?
For a few days, I've felt that NG has been reacting slower when I'm accessing here. I'm not sure if that has something to do with the trouble in question.
NG is very slow compared to just about any other forum!
One change I made during my trouble with UVP was to block Google analytics to get in between. I often see the slowness in that connection that may happen before contacting the actual website I am trying to access, waiting for google analytics. I found a description here:
https://www.infopackets.com/news/9959/how-fix-disable-google-analytics-firefox-chrome-ie . It did not by itself prevent the troubles at UVP but it seems that many sites are now faster to connect, although Google might not like it...
[Edit: Still good posting from my providers network...]