PostUp & PostDown entries have no effect when using via Proxmox

[pictosun]

Describe The Problem
I installed Wireguard and WGDashboard into a Proxmox LXC machine and everything is working fine as expected, with one point where I don't get why it behaves so?!
Even when leaving PostUp/Down blank it works without any issues?!

Expected Error / Traceback
When defining PostUp and PostDown within $wg.conf file it should also use those rules, but even when I leave them blank everything is working, I can access WAN (Internet) and all local RFC1918 networks.

I actually want to block the VPN Clients accessing all local networks but as PostUp/PostDown doesn't have any effect I can do nothing to solve this issue.

OS Information:

• OS: Debian 12.9
• Python Version: Python 3.11.2

Sample of your .conf file

[Interface]
Address = 10.40.0.1/24
SaveConfig = true
PreUp = 
PostUp = 
PreDown = 
PostDown = 
ListenPort = 51820
PrivateKey = XYZ

[Peer]
PublicKey = XYZ1
AllowedIPs = 10.40.0.2/32
Endpoint = someendpoint:6600

[Peer]
PublicKey = XYZ2
AllowedIPs = 10.40.0.3/32

[DaanSelen]

Are you absolutely certain there are no running IPtables rules. Similar to an issue we had where the first time its applied it is not removed because the predown is not removing it.
Normally a WireGuard configuration with rules is applied like this:

activate -> apply the defined rules -> working state -> deactive -> delete the defined rules according to the config.

If you remove the predown lines and you do not manually remove the actual rules they will stay applied.
Can you check that?

[pictosun]

I have nothing running. Also checked it via ssh console and looking for any iptables entries.

I defined a new configuration - all without any rules. And also there it is behaving like described above.

I do not have any predown lines available. Only within wg0.conf - but this config I do not use at all.