Contact never displays

Yes and no, these are contacts whose email addresses have changed and I don't quite remember exactly but I think for one of them, I removed the suggestion of the correct address instead of the wrong one when entering the contact. I hope you understand what I mean: when you enter the first letters, the email suggestions appear and I had two addresses, the old one and the new one, and I mistakenly hit the 'x' (delete) on the new one instead of the old one. That's one problem. How can I restore the suggestion for the new address if possible? And for the other address, I have no idea, it never appears anymore even though I had no problems with it. Just for your information, I also have a business account and the email addresses come up in suggestions without issues... ???? Thank you for trying to help me.

A contact is automatically suggested based on the frequency of exchanges with that person. Once you have exchanged emails with the relevant contact, you will be suggested again.

Unfortunately, it has been more than 4 months since it stopped working and I have to type the complete addresses every time..
And why would the other address also be gone when it was working the day before??? Thank you for trying to help me.

Try removing contacts from your list and attempt to send an email.

Have you tried sending a new email and receiving one?

Yes, of course, as I was saying, by manually typing the address, I received a reply from this contact's email... In fact, I did it for the only two that haven't worked for months. Both on Android and Windows. None of my devices suggest them anymore at all. Thank you again for your efforts. I have done so much research and testing; I didn't think it would be so difficult to get suggestions for these 2 addresses...

Which browser are you using? Does the same problem occur with another browser?

I have Chrome and Google on Android and on the computer, I've already tried Edge and then Chrome. I deleted the 2 contacts on all my devices without syncing in Yahoo and recreated them again and it doesn't get better. No suggestions.... I receive emails from these addresses, it recognizes that they are in my contacts when I click on the sender, I see all the details but it never suggests them when I start typing the letters in a new email...
Very frustrating. No suggestions just for these 2 addresses which I have already corrected or modified the address. I know I accidentally canceled the suggestion for one of the two, but as you say that by receiving emails from these addresses, it should suggest them to me again... it's not working????. Thank you for being here because I haven't seen this kind of problem for anyone on the net...

I suggest you try these manipulations from your computer.

Try deleting the problematic contacts and recreating them again. This time, save a fake email address with a non-existent domain. (e.g. message@email.test).

Once done, type the address and see if it gets suggested. If not, send a message to that fake address. You will then receive a non-delivery mail for your message.

Check if it is suggested again. If so, modify your contacts by adding the real address. Once the correct address is normally suggested, delete the suggestion for the fake address.

Then remove the fake email address from your contacts, keeping only the valid address.

Hoping this works.