Lightroom Desktop: Finding people function does not work

Have you synced your images to the Lightroom cloud yet? How long since the synced?

Yes, I have and more than a week ago.

The People Indexing is done on Adobe Servers and not your local machine. If you've synced the images to the cloud and continue working online, they should appear. I will check with the team to ss if there are any issues indexing your account. 

If you email me your Adobe ID, I will have someone take a look at your account. 

OK, I have send my Adobe ID

We've checked and your account has been indexed and should be showing people.  Can you click on your Photo Library (looks like books icon on LH Side) and then chose the People Icon.  Screenshot that and post it here please. 

As requested

One thing that may be relevant is that the People view will only show faces that appear at least 5 times in the library. At least that's the way it was when the feature was first introduced, though I haven't seen any documented change to it since then.

You can check if the face recognition aspect is working, however, by selecting any image which has clearly-shown faces then open the Keywords panel.....any identified faces will appear at the top of the panel, where you can enter the face name if known. If the image contains multiple faces, hover over each one in the list and a frame will appear over the corresponding face on the image. Once you have "tagged" a face, it should then appear in the People view (the 5 instance limit applies to untagged faces only), 

Thank you very much. Your tip to use the keyword panel is very useful and you may be correct with regards to the 5 people. Except for the photo of myself there were no 5 instances of the same person.
If this is a useful function - the threshold of 5 - is debatable.

Thank you again.

I would agree that the threshold of 5 is debatable. When I first came across it I didn't particularly like it, though I think I understand why it was implemented that way. Personally, I would prefer an option for the user to be able to modify the value of that threshold.