wireguard-windows incompatible with Win10 hotspot

[SC Lee <lsc@lv6.tw>]

(This is my first time reporting wireguard issues, please kindly let
me know if this is the wrong place.)

I'm on Windows 10, and had no luck enabling WireGuard tunnels with the
builtin WiFi hotspot feature at the same time.
When I do so the tunnel stops working, and for some reason in Task
Manager I'm seeing hundreds of Mbps of outbound traffic generated on
the wireguard interface (but no actual traffic to the internet). The
tunnel process also takes up a full CPU core seemingly due to the
generated traffic.
Upon switching off the hotspot the tunnel comes back to function.

I wonder if this is a known issue? I believe it's a common use case to
share a VPN tunnel with devices via hotspot.
This seems unrelated to the "kill-switch" feature as it happens with
or without it.
FWIW I also tried both Wintun and WireGuardNT backends, and the same
happened with both.

My environment:
Windows 10 version 20H2 build 19042.1110
wireguard-windows version 0.4.2

Thanks!