one more no access problem

[kab00]

Hello everyone,
I have a very strange problem, that I can't figure out wtf is going that wrong.
my home netwok is:
My PC connected with eth to my modem/router (ZTE), my router goes through an wall cable to my switch (tplink) to my proxmox server.
On my switch there is an ASUS access point for wireless.
For reasons beyond my understanding, my pc can connect to the VMs (home assistant and openmediavault) I have on my proxmox server through GUI, but not to proxmox itself, UNLESS I use wifi and not my ethernet connection.
Does anyone have any ideas?
I have changed cables and the switch, but not the modem/router, as it is the one vendor is providing.

Thank you in advance.

(PS: to make things even more strange, I have been able to access the proxmox gui from my PC a couple of times, by plugging and unplugging everything a couple of times.)

 

[kab00]

I tried from a different OS, and the problem persists. I have tried different ports of my main router, and different ip's, both dhcp and static.
I don't believe it to be a hardware problem, since my main pc, can flawlessly connect to the VM's on residing on prox.