FIXED - Can't connect to dedicated server through LAN

[Neonspark]

[FIX UPDATE] : I fixed it. It was one of two things. I had two network adapters on my server machine, I was using the secondary network adapter and switched to using the primary. On my PC I had secondary/tertiary IP addresses added for connecting to different subnets (I had those in there when I was configuring IP cameras with varying IP addresses, and never removed them). So I removed those as well. I think it was getting confused with multiple IP addresses on the same adapter.

 

UPDATE : I fixed the issue by adding a network switch. Both machines were connected to a router, which I thought would suffice. Maybe there is some setting in the router interfering with the communication between the two devices. 

UPDATE #2 : It stopped working again even with the switch. What the hell is wrong with this lol.

 

I cannot connect to my dedicated server which I am hosting on a separate machine using STEAMCMD with my PC on my LAN through my router. But I can connect to it with the same computer while tethered on my phone internet through the WAN. I am getting some errors which I haven't really been able to find the solution for or exact cause other than like "Lag", but I am able to ping the server at <1ms and around 1ms with 50k byte packets and of course able to connect on a not-so-ideal mobile connection as well. Here is the error I am getting :

OnP2PSessionRequest from [STEAM ID]
STEAMPS3 - AsyncTCPSocket created
Client [STEAM ID] lost connection
STEAMPS3 - AsncTCPSocket destroyed
Ending authentication session of [STEAM ID]

Where STEAM ID shows my steam ID of my account.

Any help would be appreciated, I have tried various things but cannot seem to figure it out. Ports are forwarded

• 27000 - UDP & TCP
• 27003 - UDP
• 27020 - UDP
• 27021 - UDP

But that shouldn't matter on local connection.

I have tried both connecting through "Join LAN" and "Join via IP". Both produce same results.

Thanks in advance.

Edited November 26, 2020 by Neonspark