Don't install the extra MPI.
If this worked before and now showing this issue in RSM report, try this in CMD Prompt
move "%appdata%ansys" "%appdata%ansys.old"
If this doesn't help,
Are you using VPN ?
Make sure you connect to either LAN or Wi-FI but not both at the same time
Can you try temporarily disabling all security (Anti-virus, Firewall) on the machine ?
Thanks,
Win