Numeric password not working

Hi. I'm new to the forum. I've been a casual user of Teamviewer for many years and mostly use it to access secondary computers I have from my desktop. I am currently away from my office (unexpected personal reasons) and unable to access my desktop, so I need to try and access it via my laptop (tablet really) using Teamviewer for the next few weeks.

I managed to get someone to go to the desktop and read me the numeric/assigned username (3 sets of 3 numbers) and password (4 numbers). Unfortunately I can't login; it says the password is "invalid."

I thought maybe I'd set up a custom password from a few years ago when I was working off-site, but I was using a different desktop at that time; this is a new one. I tried the only one I could think that I might have used but it doesn't work either. At this time I'm unable to send someone again to the computer site to try again, but even if I find someone I would like to have an idea of what else to try.

I'm hoping someone here can help me figure out if I'm doing something wrong, so I can get access. Many thanks in advance for your help.