@nocturnaltabernacle
Hello!
It might be an MTU size issue. By default, on Linux and FreeBSD, WireGuard might set a 1420 bytes MTU size, which is too big for some networks. Shrink it to 1320 or even 1280 bytes (the minimum accepted value) and test again.
In order to change wg interface MTU size on your BSD system, please edit the wg configuration file with any text editor and add the line:
MTU = 1320
in the [Interface] section.
Kind regards