Hello,
I have a server under esxi 6.5 which is in a 192.168.20.x subnet, and I transferred a VM which is in a 90.x subnet to this server.
But this VM which is under 90.x cannot communicate with the outside network 90.x while the VMs under 20.x can.
Sounds like you need to start by checking the host networking (virtual switches and their port groups and uplink ports), understanding also the physical network connections.
You need to check on the host whether you have 90.x subnet connected and configured.
if no, then do it or yes, then check network setting on vm configuration (right network adapter is attached).