What do you mean on "PPTP can't diag"? Can you please detail?
Also what about the MTU across the env? What MTU you have in the NSX-T deployment and outside of it?
Do you have any firewall ? Either distributed, or the gateway firewall.
Edit: There was a problem with communities so the content did not go through properly. Re-edited
As SRoland already mentioned, most probable causes are MTU or firewall. From your packet capture doesn't seem to be firewall, but there are large packets which would cause problems if MTU is not at least 1600 on physical network.
I have two 25Gb Dual Port NIC. 1st 25Gb was used for VDS and edge uplink. If the Windows 10 VM was connected in VDS, it can diag remote PPP server in internet. The second 25Gb Dual port NIC was used for NSX-T N-VDS. If the Windows 10 VM was connected to NSX-T segment, it can't diag remote the PPP server in internet. The MTU value in switch is 9000 and uplik profile is gloabl default.
Did you change the vDS MTU also? Since your edge is on the vDS that also needs larger MTU.