No,I can't ping the proxmox IP. But, I can ping computer from proxmox.so you can ping the proxmox IP but not reach it via webinterface?
I tried SSH. It is not working.did you try to ssh?
Yes. I can load websites, ping google etc.do you have regular network connectivity on that computer? (can load websites, ping outside internet)
i disabled Windows Defender, Windows Firewall etc.hmm, it's just a guess but maybe it has to do with the network not being trusted by windows, and windows firewall blocking connections?