Since a few weeks I mentioned connection issues when I try to connect to the B4A-Bridge or from my phone's browser to my Apache Server via WiFi. In this cases I have to re-connect WiFi and it works again. I assume WIN10 to be the cause (before for several years anything was ok). This just for those having the same issues.
The very first design decision behind B4A-Bridge was to make the device act as the server to avoid issues with Windows firewall. B4A-Bridge doesn't make incoming connections so it is less likely to be affected by the firewall.
Just wanted to point out that there's some issues with WIN10 +/- firewall and/or WiFi preventing a connect. Had that issue again today (internet connectivity is fast and stable but the bridge doesn't see my phone and my phone can't reach my pc (e.g. via browser to apache).