The first thing I would try is to open an incognito window in Chrome and see if you can sign in from there. Do that by clicking the three vertical dots at the top-right in Chrome and then click on the “Open a new incognito window” option.
If the VM website behaves properly in Chrome incognito that strongly suggests there is a corrupt cookie stored in Chrome. (When Chrome is in incognito mode it does not use any cookies it has stored.)
Thanks for your suggestions Coenoby. I tried what you said - just deleted VM cookies - but it is still the same. being an old guy I'm not good with computers so I think I'll just have to bite the bullet and get a new computer.