The fix for Synology devices is aimed at addressing a bug they introduced when attempting to list/open a group of folders. This is meant to address your original issue.
If you’re seeing connection issues on all protocols, there may be something else going on.
If this is on iOS, my first thought would be to check and ensure Infuse has access to Local Network in iOS Settings > Infuse. If this is off, Infuse won’t be able to connect to any devices on your network.
Beyond that, you may try switching from Wi-Fi to Ethernet (or vice versa) as this may help shake out some issues related to your network. In particular, we’ve seen at a least a few cases where a device may be able to connect while on a 2.4GHz Wi-Fi network, but does not work on a 5GHz network.