Nuendo 3.2.1 update

I have been using Nuendo 3 plus Halion for five years + with no problems at all. A month ago I had a boot drive failure and had to do a reinstall on another XPSp3 computer. At the time I updated to Nuendo 3.2.1 but immediately had problems. For some reason, the midi recording function now does not want to work at all. Midi notes are inputting (it is indicating in the midi input field but I hear nothing. The thru is on) but they stop indicating the second it goes into record. It looks like it is recording; the record bar appears whilst it is record mode but then dissapears the moment it stops recording. I have installed latest Direct X and gone through everything a great many times but I still cannot get it to work. Audio record is A OK, just the midi doesnt want to work. It is a different computer but I have very carefully installed everything I should need.
Can anyone help.

Not sure if you managed to fix it by now but there is a knowledge base article you might want to have a closer look at.
https://www.steinberg.net/en/support/knowledgebase_new/show_details/kb_show/pc-windows-midi-port-configuration-and-troubleshooting.html (Log-in required)

Maybe the port filter files help you get your MIDI back to work.